SE.RA.PH. Singularity

SE.RA.PH.: Deep-Sea Cyber-Nirvana (深海電脳楽土) was a special Singularity which emerged in the aftermath of the Human Order Incineration Incident. Originating on Chaldea's Seraphix facility in the North Sea, it occurred in the, supposedly in 2030 A.D.

Setting
After escaping the Time Temple along with three other Demon Gods, Zepar sought to help humanity realize their mental potential. However because he lost his body, he needed to seek refuse somewhere to regain his strength. He eventually found Seraphix, an oil rig secretly containing a planetarium called Celestial Body Simulator, System Animusphere, which was used to investigate leylines. There he found Kiara Sessyoin, a therapist who worked at Seraphix, and possessed her to avoid Chaldea's detection. He then used her to eventually effectively gain control of Seraphix. Using his knowledge of parallel worlds, Zepar discovered another version of Kiara, one who usurped control of the Moon Cell on the far side of the Moon. Impressed by her, he linked the two Kiara together, and used her body to convert Seraphix into SE.RA.PH and give it form. Afterwards though, Kiara plunged the Seraphix staff into mass hysteria to Zepar's disgust. She then seduced the personnel to open the planterium, where she placed 128 Master candidates in the Coffins found there to summon 128 Servants, which killed them. As well BB, Meltlilith, and Passionlip were salvaged from Kiara, as she had absorbed them in the Moon world, to serve her. Jealous of the delight she felt from Zepar's memories, Kiara sought to use SE.RA.PH to become a Beast. Zepar realized at this point that he lost control of Kiara's body, and he was forced to reside only in her pinky finger. Eventually though he was forcibly expelled, and quickly disappeared. Kiara then enacted her plan to descend SE.RA.PH down into Earth's core so she may fuse with the planet. She infected Meltlilith and Passionlip with parts of her, Karmaphage, to turn them into Sentinels to serve as SE.RA.PH's self-defense mechanisms. She also ordered BB to begin the Holy Grail War while continuing to manage SE.RA.PH. At some point though, the Moon Cell sent a copy of the original BB to Seraphix on a one way mission to prevent Kiara's transformation into Beast. She then switched places with the other BB as manager of SE.RA.PH while the other hid at its bottom.

BB recreated the Moon Holy Grail War, but compared to its original more organized battle royale counterpart, this one turned into a massacre. The Servants succumbed to their desires, and began to commit several atrocities. One particular Servant by the name of Suzuka Gozen was turned into a Sentinel by BB, hoping to win the Grail War for her Master, not knowing they were already dead. Meanwhile, the corpses of the Masters inside the still active Coffins were used as biological circuits to continuously summon Servants. Eventually Meltlilith and Passionlip decided to rebel against Kiara, and became the Servants of a version of Ritsuka. They eventually won the Holy Grail War, and fought Kiara at the planetarium. They lost however, and BB's time leap failed due to Meltlilith and Passionlip still being Sentinel. Meltlilith's arms were torn apart, and Ritsuka was killed for her transgression. Passionlip then used Virgin Laser - Palladion to launch Meltlilith upwards at the speed needed for time travel. Meltlilith vowed to redo everything so she can help Ritsuka free the Sentinels from Kiara's influence. She then met a past version of herself at the chapel, and shared her memories with her. The past Meltlilith then committed suicide without hesitation to prevent Kiara from realizing there were two Meltlilith.

History
Chaldea prepares for their regular report from Seraphix. It is an Offshore Oil Rig once owned by Marisbury Animusphere that provides Chaldea with resources. Chaldea attempts to contact the facility, but they receive no audio or visual, despite both audio and video feeds being active. They receive an SOS message, saying everyone is being digitized. The connection with Seraphix is then abruptly cut, so Da Vinci authorizes the use of Sheba to observe Seraphix. However, a staff member reports that Seraphix seemingly no longer exists, with no signs of a Singularity. Chaldea soon receives a video message from BB. She reveals Seraphix no longer exists in the current time period, and tells Chaldea to check the Mariana Trench in 2030 A.D. The staff confirm Seraphix's location, revealing its currently 200 meters before the surface along with the existence of a Singularity. BB tells Chaldea to save Seraphix's staff before the oil rig sinks down to 10,000 meters while also dealing with the Singularity manifesting there. Leonardo da Vinci explains rayshifting to the future is impossible, but quickly realizes BB can verify Ritsuka and others' existence since 2030 is BB's present. BB warns Seraphix will reach the bottom of the trench in a few hours, at which point it'll be destroyed by the water pressure. Ritsuka, Nero Claudius, Tamamo no Mae, and EMIYA then rayshift to Seraphix. However BB hacks the rayshift to separate the group to random locations in the facility.

Ritsuka arrived in a strange locale when they're contacted by BB. She tells them that they've been plunged into a Holy Grail War, a battle to the death between 128 Masters. She then explains they're in Seraphix, but it's been digitized into Pseudo-Spiritrons. She says they'll retain any any experience, knowledge, and power sources once they return to the physical world. She reveals they're at what used to be Seraphix's front gate. She tells them to discovery the mystery of the digitization before SE.RA.PH sinks to the bottom of the trench while surviving through the Grail War. After BB ends communications, Ritsuka tries to find Nero, Tamamo, and EMIYA when they're ambushed a female swordsman. They're saved by another girl, who reveals the female swordsman is Suzuka Gozen. The girl introduces herself as Meltlilith, and has Ritsuka contract with her. She then fights Suzuka, but her attacks are reduced by 90% by Suzuka's karmaphage. Suzuka retreats however when Meltlilith said her attacks have deadly viruses. Meltlilith decides they should enter the facility from the main oil deck cable area, given the front gate is completely digitized. She warns Ritsuka that they'll eventually be disintegrated if they stay too long in digitized areas like the corridor they're currently in. In such areas, humans are converted into data after a few hours, and imported to SE.RA.PH. Even Servants will only last a few days. Meltlilith warns Ritsuka everyone will be converted into data well before SE.RA.PH reaches to the bottom of the trench. Meltlilith reveals time in SE.RA.PH passes a hundred times quicker than in reality. She also explains that while SE.RA.PH is based on Seraphix, it is significantly larger. She then decides they need to find a safe area to serve as a base before Ritsuka gets digitized.

After fighting a bit through SE.RA.PH, Meltlilith learns more of the situation from Ritsuka. Ritsuka asks her why she chose to protect them, but she asserts it was because she though they were important when BB payed extra attention to them. Moving on, Meltlilith explains that SE.RA.PH is a digital labyrinth loosely based off of Seraphix. However, the current SE.RA.PH is only an imitation of the original, which is significantly larger. She explains the original SE.RA.PH was a city-type engine designed to run the Moon Cell Automaton, a construct made of photonic crystals inside the moon. She continues SE.RA.PH is also a world where many humans, NPCs, and AIs live in. It was the site of the Moon Holy Grail War, the Moon Cell itself being the prized Holy Grail. Meltlilith explains the Moon Cell chooses which human will use, but as it is an observational device, it cannot know the quality of the human. As such, it created the Holy Grail War as a fair and impartial albeit violent way to weed out the candidates. It invited 128 Masters to SE.RA.PH to compete in the Holy Grail War, choosing the surviving Master. As a result, the Moon Holy Grail War turned into a slaughterfest, similar to Ritsuka's current situation. However, the difference is that the Moon Holy Grail War was a tournament, unlike the free-for-all Ritsuka is experience. The Moon Holy Grail War was divided into seven rounds, and the administrators deciding who fought who, which Meltlilith believes it was more rational than the current one. Ritsuka ask her why she looks like BB, so she explains BB is a high-grade AI who was stationed on the Moon during the Grail War. BB was designed to keep Masters healthy during the war, but she bugged out and started to style herself a ruler of the moon. Her prime directive of protecting humans eventually turned managing humans as a result of several errors. BB even tried to usurp control of the Moon Cell, but she lost to a human. Meltlilith then reveals she is an aspect of BB's personality she removed from herself; Meltlilith is the Alter Ego created from BB's sense of pleasure. As she and the other Alter Egos were created from BB, they all look like her. She then warns Ritsuka of a Servant up ahead. The Servant is revealed to be Gawain, who find it hard to believe Meltlilith is a Heroic Spirit. She confirms she isn't a Heroic Spirit, but she realizes Gawain wasn't among the 128 Servants. Gawain then notices Ritsuka, glad he has finally found them after being separated during the Rayshift. Ritsuka is confused, but Gawain asserts he was one of three Servants who rayshifted with them. Ritsuka recalls how Nero, EMIYA, and Tammao rayshifted with them, but Gawain continues to assert his claim. Gawain then decides to join Ritsuka in order to resolve the situation and return them safely to Chaldea. After Ritsuka explains the situation, Gawain thanks Meltlilith for saving Ritsuka, but he remains suspicious of her. Meltlilith decides they need to find Ritsuka's other Servants in addition to finding a safe area. BB then suddenly appears before the group, deciding to punish Ritsuka for breaking the rule of having more than one Servant. Gawain whispers to Ritsuka that he'll try to capture BB, but she asserts nothing happens in SE.RA.PH unless she wants. She then summons Robin Hood, who she orders to kill the group. The group kill Robin, but Gawain is confused by the slot machine that appeared at the battle's start. BB explains she created it to interfere with the battles regardless of the strength of Masters and Servants. She tells Ritsuka that she'll let them go free if they either win her Grail War, or if they discover the secret behind SE.RA.PH. She states she will continue to watch their progress. Meltlilith asks her why she personally appeared, to which BB answers she did so to personally cause mischief. BB asks Meltlilith why she joined the humans, to which Meltlilith claims she is following her own rules. She also explains to BBB that she shouldn't care how she spends her time, as long as she fulfills her ultimate as role as a Sentinel. She then tells BB to go away, so she and the others can explore in peace. BB reveals she locked several SE.RA.PH's passageways, which she'll discreetly open for a fee. She also warns the group not to explore too far, otherwise they'll encounter stronger Attack Programs and Sentinels, special Servants tasked with guarding SE.RA.PH. She then explains that SE.RA.PH is like the digital embodiment of humanity's inner world, which used to be also called the Sakura Labyrinth. She continues the Sakura Labyrinth and the Sentinel convert huamn emotion into defensive mechanisms. Each Sentinel is created a powerful passive skill called Karmaphage, which makes them nigh unbeatable to a normal Servant. While warning the group to keep away from the Sentinels, BB also says they need to defeat the five Sentinels, who each guard one fifth of SE.RA.PH, if they wish to fully investigate SE.RA.PH. She then resurrects Robin, but she sends him away when he begins to complain. Before leaving, she corrects Da Vinci's assertion that Rayshift to the future is impossible. She states it isn't inherently impossible, however it is for Chaldea as they cannot rayshift past the year 2019.

Later, the group defeat Gilles de Rais. Ritsuka and Gawain were confused by his behavior, but Meltlilith explains most Servants in SE.RA.PH have already succumbed to their desires. Gawain then questions why they haven't encounter any Masters yet. Meltlilith reveals the Masters all died a long time ago as soon as they summoned their Servants. Gawain questions the Servants are still fight even though they don't have a reason to, but Meltlilith reminds him only the Servants from Chaldea are acting rationally. She starts to ponder if BB is responsible when she notices something. Ritsuka thinks it's a Holy Grail, and touches it despite Gawain's warning.

Upon touching it, Ritsuka see the final memories of a Seraphix crew members. On January 2019, every ship set ablaze, the helicopter was destroyed, and Seraphix lost all communication with the outside world. As well, parts of the base were digitized. By Feburary, the crew was down to about a hundred survivors, and they moved to the Central Command Room where the digitization occurs the least. They decides to wait till May for Chaldea to notice Seraphix's situation. However, Chaldea never came, and Seraphix's crew soon became violent. In March, they executed the director, Hideyasu Ajima, for not anticipating the situation. Next, the assistant director was executed for failing to resolve the situation, then a woman who lost the key to the cleaning room, Then, the doctors, who became useless when the medicine ran out, and the people who went against Beckman were sacrifice to the monsters outside. Other people were executed for mild transgressions or utter xenophobia. Despite all of this, the remaining crew remained optimistic the situation would be resolved in a few days. However in April, they learned the time difference between digital and reality, meaning any help from Chaldea could take more than fifty years. The memory ends with the crew members being killed by a sledgehammer by Beckman loyalists for breaking the rules.

The group eventually come to a fork; one path leads to the Chest, formerly the Central Command Room, while the other leads to the Thighs, formerly the dock and heliport. Gawain understands each area is named after a part of the body. He correctly assumes the current area is the Hair, and asks what the area originally housed. Meltlilith answers it housed the submarine cables, pump, and power plant. She says it's relatively safe, but the important area is the Chest, where the group may find survivors. Tristan then suddenly appears, disappointed at Gawain for associating with Meltlilith. He's surprised to see Ritsuka, as they're the only Master he's encountered, and mentions he's already killed seven Servants. However, he's also disappointed by Ritsuka for associating with Meltlilith. He tells Ritsuka and Gawain to move of his way so he can kill Meltlilith. Gawain asks Ritsuka whether they should move or stay after warning that Tristan's arrows pierce all he sees without mercy. They decide to stay, so the group are forced to fight Tristan. During the battle, Tristan tries to kill Meltlilith with his arrows, but her liquid body negates the attempt. She then pins him down, and decides to spare him. She tells Gawain to finish him, but he refuses to do so as it is her victory. He realizes she wants to let Tristan go, but she refutes him. Ritsuka and Gawain decide Tristan will join them despite Meltlilith's protests. Tristan accepts despite Meltlilith being part of the group. After hearing SE.RA.PH was originally Seraphix, Tristan reveals he was only summoned ten days. Gawain asks him if he participated in the Grail War, to which Tristan answers he explored SE.RA.PH to find and capture BB while killing any insane Servants he encountered. He then recalls an Alter Ego he's encountered multiple times, each time forced to retreat to avoiding being crushed. He calls the path leading to the Chest Breast Valley, the domain of the Alter Ego. Meltilith reveals the Alter Ego is Passionlip, who was born from BB's love and hate.

The group come to the path leading to the Chest when Ritsuka begins to feel the effects of digitization. A woman then appears, mistaking Ritsuka's Servants as the same the insane ones she encountered so far. She calms down though when she notices Ritsuka's uniform is that of Chaldea. She introduces herself as Marble Macintosh, robotics operator on Seraphix. Gawain introduces himself and Ritsuka, and asks her what she knows. Marble doesn't answer though when she notices Meltlilith. She asks the group why they have an Alter Ego, believing humans and egos are supposed to be mortal enemies. She tells Gawain to kill Meltlilith when she notices what she was running from has caught up to her. She tells the group to run, as her pursuer crushed all new 128 Servants when they arrived here earlier. The pursuer is revealed to be Passionlip, who Meltlilith reveals to be one of the Sentinels. The group fight her, but they're forced to retreat when she uses Trash & Crash on the passageway. with the passageway now compressed into a cube, the group return to the fork with Marble.

Gawain asks Marble what she saw in the Central Command Room. She answers the Command Room, and the only survivors besides her are Arnold, Ms. Trapayne, and Holly. However, the only people left in the Command Room are her and Arnold. She ran away though when they began to fight over food. Meltlilith thinks they should abandon Marble, but Ritsuka decides they should find a safe area. Asked by Gawain if she knows a safe area, Meltlilith answers there is a building in the Thighs with magical protection, and too many indecipherable elements to be digitized. It is a christian chapel built to provide Serahpix's crew with spiritual support. Tristan reveals Vlad III guards that area, so he must be defeated if the group wish to get to the chapel. As the group travel towards the chapel, they notice many Servants and humans impaled on Vlad's stakes. Vlad prepares to fight them, and reveals a Demon God inhabits his body. As Vlad disappears with his defeat, Ritsuka asks him about what he said earlier, but he doesn't answer. Instead he tells them that EMIYA is in the chapel, but says he cannot be trusted.

The group enter the chapel where they meet, not the regular EMIYA, but EMIYA Alter. In answer to Meltlilith's disappointment, he reveals BB switched him out with his other self. After Ritsuka explains what happened so far, EMIYA Alter replies he's been watching from the chapel roof. He then reveals there is a terminal hidden behind the altar that contains a report. However it is locked to even Servants and Alter Ego, so its key needs to be found. The group believe the report may contain a clue, and decide to search for the key tomorrow. Meltlilith decides to rest outside when Ritsuka notices a broken ceramic figure. In her thoughts, she thanks Ritsuka for noticing "her", even if it's only the remains.

After purchasing the terminal key from BB for a large amount of Sakurament, Ritsuka uses it on the terminal. An audio guide in the terminal warns the records can only viewed by one person at a time, and that they'll be deleted after playback has concluded. Marble explains the terminal sends the data directly into the brain of whoever is viewing the records. The terminal then plays the records from February 7, 2019. The record keeper introduces themselves as a therapist, who was invited to join Seraphix back in 2016. They go on to recall everyday life in Seraphix while they dealt with their patients at the church. After listening to so many complaints, the therapist began to question why Seraphix was built. Then on January 2019, Seraphix lost all contact with the outside world, and strange happenings began to occur. The therapist joined the medical team to help the victims when they noticed a monster with many eyes that preys on human minds. On Feburary 2019, they began to change like the rest of the crew, losing all sense of morality. However, their obligation to their job helped them keep their rationality. On March 2019, they are severely injured and thrown into the church, which they quickly lock. They decide to leave a record behind, terrified something more terrifying than the hysterical crew is eating away at their mind. They then begs somebody to not the planetarium, to not let its experiments continues, and to kill them. After the record ends, Gawain believes the crew summoned BB of their own accord. Meltlilith reveals the planetarium is in the middle of SE.RA.PH, and that it's the source of the digitization. Ritsuka, Meltlilith and Gawain decide to continue explorable while Tristan and Marble stay behind in the chapel. EMIYA Alter leaves to kill the Servants to keep the others' exploration unimpeded as Gawain believes.

The group discover the upper part of Arm, and Gawain asks Meltlilith if she knows what was originally here. She guesses it originally held robotic operations, which was used for seabed investigations. She continues if they were continue to the Thenar, they should find the Arm used to examine the soil. Ritsuka asks if the Foot area is the same, but Meltlilith answers the legs had more destructive purposes. BB then suddenly contacts the group, and reveals SE.RA.PH is the only thing keeping the humans alive. She also tells them of her updated stock of Gate Keys and various other items. She then introduces the next Sentinel, Tamamo Cat whose been subjugated by BB. After Cat is defeated, BB is so annyoned at her not using her Karmaphage, she sends her through a trapdoor while ordering to remain at her designated position. BB tries to end contact, but Meltlilith stops her to ask about the 128 new Servants Marble mentioned earlier. BB answers she summoned them herself, and she'll continue to do so until a proper recreation of the Battle of the Time Temple is made. Gawain asks her how she knows of that battle, but she answers the group's action lead to draw the connections between the events. She then tells the group that there's only one real world hour left before SE.RA.PH hits the seabed before ending contact.

The group eventually make it to the Flank Separator, which used to house separator devices for desalination, and where collected resources passed through before packages. A human memory then appears, and Ritsuka promptly touches it. It is the memory of a man who was brought to Seraphix to serve as a fixer, someone who kill those who would disrupt operations or leak secrets. He recalls how the survivors divided into factions, and how was chosen to enforce Beckman's laws when he took control. While reveling in dominating others, he began to regret when he learned about love from a certain woman. He declares his complete and utter devotion to her, ready to do absolutely anything for her. He claims he doesn't fear anything except the fear that the woman will despise him, and discard him. The memory ends with the man declaring he would rather watch the world burn than lose the love he found.

The group, joined EMIYA Alter are nearing the area's final zone, which is assigned to a Sentinel as Meltlilith explains. Gawain asks her what Sentinels are, as he was under the impressions they were all Alter Egos. Meltlilith admits Alter Egos were originally salvaged to be made into Sentinels. However a Sentiel doesn't need to be a Alter Ego, as BB can anyone she wishes into one. She only needs a Spirit Origin that can handle a Karmaphage. Meltlilith explains how she and the other Alter Egos were originally made to adhere to the emotions they were born from, however they eventually learned to control their behavior. She then recalls a human who once told her that she was truly alive. The group eventually encounter Cat, and fight her. After she is defeated, EMIYA Alter seemingly fatally shoots her. However she gets up alive while revealing she was planning to rejoin Ritsuka's side, only joining BB to survive. EMIYA Alter reveals he used his knowledge of Magic Circuits to target and destroy the parts on Cat's Spirit Origin infected by the Karmaphage. Now free of BB's control, Cat joins the group.

Returning to the chapel, the group discuss whether to continue exploring, or find a way to escape. Gawain asks Marble if they were any other facilities in Seraphix besides the ones he and others visited. She answers there is the soil survey room, the resource compression and drying area, and the dump. Gawain has Meltlilith reveal her knowledge of the other facilities. Understanding they won't discover anymore on the front side, Meltlilith decides to tell the group of the other side. She explains SE.RA.PH has a two layer structure, with a front side and back side. She reveals she was originally a back side Sentinel, but BB scrapped her after she disobeyed. EMIYA Alter asks her how they get to the back side. Meltlilith answers humans and Servants cannot cross the border between the sides, and only Sentinels can cross it. Thus, she says the only way to get to the back side would to flip SE.RA.PH over, but she doesn't know how. Ritsuka however realizes a way to do so after listening to Cat's nonsensical rambling. Gawain asks if getting to the back side will get them to the Central Command Room, to which Meltlilith answers it will. She continues that once the group arrive on the back side they only to reach the Command Room's coordinates, and flip SE.RA.PH again to arrive at the Chest. While this method will help them bypass the passageway Passionlip destroyed, they will still need to fight her. Meltlilith reveals the restraint on Passionlip control her, so if they're destroyed then she likely help the group.

Leaving Tristan and Marble at the chapel, the group, joined by Cat and EMIYA Alter, soon arrive at the Flank Separator. Following Cat's advice, Ritsuka hits the Separator, and SE.RA.PH starts shaking. BB contacts the group, and sends a Sentinel, Elizabeth Bathory, to punish them for their transgression. After the group defeat Elizabeth, BB decides she'll let them go to the back side when she notices Passionlip approaching despite not being ordered to. Meltlilith urges Ritsuka to hurry up with flipping SE.RA.PH over before they're all compressed by Passionlip. Gawain holds her back, as Ritsuka finally succeeds in flipping SE.RA.PH over.

With the exception of Gawain, the group arrive on the back side. However, they're greeted by Suzuka, who soon fights them after being insulted by Cat despite orders by BB to escort them. After the fight, Cat asks Suzuka why she became Sentinel, confessing she became one out of necessity to survive. Suzuka boasts BB recruited because of her winning streak, and confesses she only care about winning the Grail War. She then gets a phone call from BB, who orders her back to the temple, and not to fight the group. She questions the order, but she stops when told Chaldea Servants don't count. She then hangs up, assuming BB has a plan. She tells the group to check out the Nape if they plan to head to the Command Roon. She then leaves saying the Seraphix's crew brought the crisis on themselves, and Seraphix was never just oil rig. EMIYA Alter says he investigate the front side beforehand, and found it nearly all the fatalities needed for a oil rig. Thus, he questions why Suzuka said what she did, and wonders where they can find evidence. Cat then remembers they still need to go back to the front side and save Gawain. EMIYA Alter however opts instead for heading towards the Chest, and flipping SE.RA.PH to get to the Command Room while avoiding Passionlip. He notices the area corresponds to the Front Gate on the front side, and asks Meltlilith what it was used for. She answers that it was a gate reserved for special employees who were mages. EMIYA Alter guesses the gate used solely by employees who reported directly to Chaldea. He quickly remembers though that everyone at Seraphix worked for Chaldea. He then realizes that the only people who would use the gate would those who work directly under Chaldea's owners, the Animusphere family. Cat then tells the group she heard an alarm telling them to present a pass now, and fail to do so in five second will result in their immediate termination. EMIYA Alter quickly realizes it meant termination literally, as he sees enemies approaching. After defeating them, the group prepare to continue exploring when Robin arrives. He gives them a message from BB saying Passionlip is waiting for them on the front side, and they should submit to her since they can't possibly beat Passionlip. He also tells them BB developed a secret weapon that can break "the shackles" on Passionlip's heart, and it can used also to remove her restraints. EMIYA Alter questions the point of defeating Passionlip, but Ritsuka decides they'll free her. Robin then takes everyone except EMIYA Alter back to the front side. BB then appears to offer EMIYA Alter a chance of survival if he kills every surviving human on SE.RA.PH, and captures Ritsuka. If he does that he'll learn the secret about SE.RA.PH, as part of his job as Counter Guardian. EMIYA Alter promptly agrees to join BB.

The group arrive back at the front side being encroached by Attack Programs and Passionlip. After they defeat the programs first on BB's order, BB reveals the only way to defeat Passionlip is to use the Maiden Coaster, a battle to conquer the mind. Meltlilith realizes that it's connected to the Code Cast Ritsuka earlier. She then asks BB if it's possible, as she thought only humans could analyze human minds. BB answers she can manage if the target is a Karmaphage infected Servant. She continues that Ritsuka will need place their hand on Passionlip's chest, but the group will need to pin her down first. Robin and Meltlilith argue about their inability to overpower Passionlip when a severely injured Gawain suddenly arrives. He confesses he also wishes to save Passionlip, and then holds her long enough for Ritsuka to touch her chest. Upon doing so they are converted into Psuedo-Spiritrons by BB in order to enter Passionlip's mindscape. After being defeated in her mindscape, Passionlip collapses followed by Gawain. However he quickly gets back up, and decides they should let Passionlip rest at the chapel. After Cat returns to the chapel carrying Passionlip, Robin sneaks off somewhere. Ritsuka, Meltlilith, and Gawain then continue onto the Command Room. However, to their shock, they find a Demon God inside. After they kill it, a man emerges from hiding, and correctly surmises Ritsuka as a member of Chaldea. He introduces himself as Arnold, secretary to the director of Seraphix. He asks how the rescue is proceeding, and if the digitization has stopped. He becomes disappointed in Ritsuka though when he learns they're only one from Chaldea, and how long it took them to get into the Command Room. Meltlilith asks him what happened to the rest of the staff, but he's shocked that an Alter Ego is with the group. Ritsuka and Gawain convince him that Meltlilith is an enemy of BB, and he answers he's the only survivor. He recalls a woman who ran away, but he doubts her survival. He also mentions a corpse of another staff member is in the nearby locker, having died of a drug overdose. Ritsuka tells him that Marble, the woman who ran away, is alive to his surprise. Gawain says they should look over the records kept in the room, and then search for the Planetarium. Arnold tells the group that outsiders aren't allowed to view the records without authorization, and insists the planetarium doesn't exist. He continues they need authorization from the director of Chaldea, the head of the Animusphere family, to access the records. Meltlilith however reveals the data was deleted long before they arrived, leaving them on their alone to find the planetarium. She then notices that a passcode for the chapel terminal that wasn't there before. Gawain wonders what it's doing in the Command Room, to which Arnold replies that a woman commuted from the chapel to provide therapy to the religious staff members. However, they eventually came to believe God abandon them, and killed the therapist slowy. She left the passcode behind before she died. Ritsuka then asks about the Demon God, which Arnold says suddenly emerge from the floor one, and killed and consumed the people who murdered the doctors. Beyond that though, the Demon God left the others alone if they kept their distance. Ritsuka and Gawain point out how it felt different from the Demon Gods they're familiar with, as if it was empty. The group then decide to return to the chapel, taking Arnold with them, who properly introduces himself as Arnold Beckman.

Back at the chapel, Passionlip introduces herself to everyone, and decides she'll help to thank Ritsuka and Gawain. Tristan allows her to join as he sees she and Meltlilith are not under BB's control. He's concerned though EMIYA Alter will kill them, but EMIYA Alter insist he is only here to exchange information. Marble wonders to herself if Arnold was wrong to command the others to attack the Alter Egos if it was possible to talk with them. Arnold doesn't object since Ritsuka is the leader, then goes up to the second floor with Marble to rest. Ritsuka then uses the passcode found in the Command Room to access another record on the terminal. The record starts with its keeper confessing they are recording it in their sleep through an unknown method. They then introduce themselves as the Demon God Zepar, but correct themselves that they've been possessed. They then reveal Seraphix was created to run a certain experiment. While it functioned as a oil rig, it also contained a secret mage's workshop deep inside. This was done to avoid the watchful eyes of the Lords, and because the experiment could only be conducted on the seabed. The record keeper then reveals the resources brought into Seraphix, also contained human subjects of varying Magic Circuits and Rayshift compatibility. They then say it's possible to revert Seraphix back from its partially digitized state. They reveal themselves to be the therapist from the previous record, and they were contacted by Zepar several days after locking themselves in the chapel. Zepar commends humans for defeating him, and expresses particular interest in the amount of energy the human mind can potentially generate. He wishes to help humans realize that potential, but his body was destroyed with his defeat. Zepar prepares to possess the therapist while also apologizing for it. The therapist tries to convince Zepar to possess someone else, but Zepar rejects it as human bodies aren't significantly different. Zepar assures the therapist that he won't erase her mind just yet. He continues that someone will come to destroy him once it's been determined a Demon God still lives. Zepar then says they need to rest to regain their strength to gain the time to build their world. For that reason he'll pose as the therapist to learn everything they can about Seraphix. Zepar continues that in time he will convert Seraphix into another world, and be reborn as a Demon God, which is when he'll free the therapist. Afterwards, he'll reward the therapist for her suffering by sparing only her. Zepar then possesses the therapist, and uses them to transform Seraphix. The therapist reveals the next step of Zepar's plan after Seraphix is completely digitized is "connection". She further reveals Seraphix was rayshifted to 2030 to avoid Chaldea from discovering Zepar's plan. From there, it will sink down into the Mariana Trench, and once it reaches the bottom, Zepar will be reborn. The therapist then reveals she was disposed by Zepar after BB was summoned to be his new partner. She says she did everything to save Seraphix while feeling her consciousness fade away. She ends the record urging for someone to not let SE.RA.PH reach the seabed to prevent Zepar from being reborn. While the others are shocked a Demon God is behind the digitization, Meltlilith confesses she knew Zepar summoned BB to serve as his navigator by running SE.RA.PH. She also reveals BB placed a number of restrictions on her and Passionlip to specifically prohibited them from revealing SE.RA.PH's true origin and purpose. She is surprised though BB allowed a record revealing Zepar's plan to exist. Gawain is surprised to discover one of the four Demon Gods to escape Time Temple is hiding in Seraphix. EMIYA Alter surmises Zepar somehow learned of the Moon Holy Grail War from an different timeline, and summoned BB to transform Seraphix into SE.RA.PH so he can be reborn. Tristan then questions why BB summoned Servants, but Passionlip is unable to discern BB's way of thinking. Meltlilith reveals the Servants were summoned in order to procure the Psuedo-Spiritrons needed to keep SE.RA.PH running. The group unanimously decide to defeat the Sentinels and BB before stopping Zepar's plan. Outside the chapel while others are resting, Meltlilith shares her data with Passionlip so she can fully understand the situation. She asks her to led her Virgin Laser - Palladion, and says the three of them will defeat that monster this time. Later in the chapel, Gawain is ambushed and consumed by something.

The next morning, everyone discovers that Gawain was killed while they were sleeping. Meltlilith and Passionlip are accused by Tristan, EMIYA Alter, Arnold, and Marble because they're Alter Egos. Meltlilith points she and Passionlip wer outside at the time, and Gawain was too wary of her to allow to ambush her. Seeing the lack of evidence, Tristan asks Ritsuka to continue exploring SE.RA.PH while continues to stay behind to protect Marble and Arnold. He also asks EMIYA Alter to accompany Ritsuka so they can keep an eye on him. Tristan confesses he is suspicious of both the Alter Egos and EMIYA Alter, but he understands the Alter Egos wish to protect Ritsuka while EMIYA Alter isn't especially concerned. Thus, he will have the Alter Egos protect Ritsuka while EMIYA Alter keeps an eye on the Alter Egos.

Returning to the back side, the group defeat Julius Caesar. EMIYA Alter asks Meltlilith if Suzuka is the only Sentinel left on the back side. She answers she isn't sure what area Suzuka is using as her temple, but she guesses it's at the center of SE.RA.PH, the Spine. She also reveals Suzuka has been given the strongest Karmaphage, and she was put in charge of the back side. Before heading to the Spine, EMIYA Alter suggests to Ritsuka to activate the Maiden Coaster on Suzuka to negate the effects of her Karmaphage. The group later arrive at the gate leading to the Spine, forcing them to purchase another gate key from BB. Arnold then contacts them using equipment he had Tristan bring from the Command Room. He orders them to flip SE.RA.PH. once they're at the spine, saying they should arrive at the planetarium. He also reveals SE.RA.PH will the reach the bottom of the trench in 15 real world minutes, or 24 hours in SE.RA.PH time. He ends his transmission after saying he'll meet them at the planetarium.

Entering the Spine, the group discuss Suzuka's motives while traveling to her temple. They soon arrive at the temple where Suzuka greets them ready to fight. She reveals she and Tristan are the only Servants left in the Grail War, so she'll kill him after killing the group. She proves too fast and strong for them to pin her long enough for Ritsuka to open her Maiden Coaster. Arnold suddenly contacts the group to tell SE.RA.PH has started to sink faster, so he orders them to defeat Suzuka quicker. Ritsuka ask Suzuka if she's fine with being Zepar and BB's flunky, which angers her. She insists she only belongs to the Master who summoned her, and confesses she wants to win the Grail War to grant their final wish of not wanting to die for nothing. In respond to her conviction, Cat uses her ultimate technique to trap Suzuka. Ritsuka uses this opportunity to open Suzuka's Maiden Coaster with the key they bought from BB earlier. After she's defeated in her mindscape, Suzuka tries to jump off a cliff as she begins to disappear for some reason. Cat stops her though, and convince her to join them. Meltlilith says they should flip SE.RA.PH now when a Demon God emerges from the ground. Suzuka reveals the dump is beneath them, but they should destroy the Demon God first. After the Demon God is destroyed, Arnold contacts the group to tell them that there are only eight hours left before SE.RA.PH reaches the seabed. He orders them to return to the chapel, but Ritsuka decides they'll rescue Meltlilith from the dump that she was knocked into earlier. Arnold repeats his order, but Ritsuka still refuses to give up on Meltlilith despite EMIYA Alter and Tristan saying it's impossible to save her now. Suzuka however has EMIYA Alter lend her a tow cable so she and Ritsuka can be lowered into the dump. EMIYA Alter warns though the cable can only extended with magical energy to about five kilometers. Ritsuka and Suzuka then get ready to lower themselves down into the dump.

Meltlilith awakens to find herself into the dump. She tries to get up, but her legs were broken by the fall. She recalls the time she spent with a different Ritsuka, and prepares to submit to her fate when Ritsuka and Suzuka arrive to save her. Suzka protects Meltlilith and Ritsuka from the monsters, but they seem to be innumerable. The trio try to retreat, but they find the cable has been cut. Tristan arrives to save them, but now he's also trapped with them. Meltlilith warns the others they can't let Arnold into the planetarium, as he'll self-destruct from the desires it will unlock in him. She then realizes she is in the Calf, and BB arrives to confirm the Cruel Thenar, Meltlilith's former workplace, is ahead. BB prepares to send the group further down into SE.RA.PH, warning it'll reach the seabed in five five and a half hours.

Meanwhile at the chapel, Arnold confesses he was responsible for the deaths of most Seraphix's staff. He ponders on how to force Ritsuka into following his orders when EMIYA Alter arrives. He tries to order him to retrieve poison from the sickbay, but EMIYA Alter kills him before he can finish. He then kills Marble, revealing he needed all Seraphix's staff dead to prevent Animusphere's experiment from being repeated. He prepares to go and destroy the planetarium when a mysterious voice criticizes his ruthless and callous approach. He recognizes the Spirit Origin pattern, and the voice in turn recognizes him. They reminds him of the cult he slaughtered, even though the only evil person there was the woman who founded it. They reveal themselves to be that same woman he killed after massacring the other members who tried to protect her. She also reveal she was the once that consumed Gawain, and prepares to EMIYA Alter next.

The group are sent by BB to the Cruel Thenar, Meltlilith's former designated area. Meltlilith explains that on Seraphix, it was officially used for oil excavation, but secretly it was used to investigate Leylines. She summarizes it as investigating the Earth's brain waves, but she doesn't fully explain it since time is short. She then asks Ritsuka to open her Maiden Coaster, knowing they brought the key to her heart from BB earlier. Passionlip says if Meltlilith is defeated in her mindscape, her Karmaphage will will also disappear, and the area will be unlocked. Ritsuka opens Meltlilith's Maiden Coaster, and eventually defeats her in her mindscape. Even though she said there wasn't much time left, Meltlilith sits down for some reason. Tristan questions her since they find the planetarium. She then transports everyone to front side in front of the chapel. The group enter the chapel to rest there, but they see no signs of Arnold, Marble, or EMIYA Alter. BB then makes an announcement that SE.RA.PH will soon reach the seabed, and offers the chance to fight her at the planetarium. Ritsuka, Tristan, Cat, Passionlip and Suzuka leave for the planetarium while Meltlilith stays behind.

The group arrive in BB's studio in the planetarium, and fight her. After BB seemingly disappears, the room becomes pitch black, and sound is also muffled. Someone tries to ambush the group, but they fail in their attempt. The group then find BB's studio gone, and discover 128 Coffins with people still inside. Suzuka realizes they're the Masters who summoned the 128 Masters, and demands EMIYA Alter to explain things. He reveals Seraphix's core is called the Celestial Body Simulator, System Animusphere. He continues that it is here Zepar used the Master candidates to summon the 128 Servants. He also reveals the Masters in the Coffins died long ago, but long as the Coffins are actives, they still be used endlessly as biological circuits. He continues the corpses summoned 128 Servants continuously until Ritsuka arrived. He confesses he destroyed the Coffins' power source, and prepares to kill Ritsuka to remove all knowledge of the planetarium's existence. Robin then suddenly arrives, and helps the group defeat EMIYA Alter. After he's defeated, Marble suddenly appears, and Cat demands she reveal herself. Marble changes into true self, reveal Marble was merely an artifice. She reveals she was the therapist who worked at the chapel, introducing herself as Kiara Sessyoin. She reveals after many conversations with Zepar, they reconciled and decided to try to save people. She then reveals herself to be Beast III, the Beast of pleasure. She explains SE.RA.PH is shaped like a human body is because Zepar transformed Seraphix into her body. Robin asks her if she was the one summoned BB while under Zepar's influence. Kiara confirms such, and reveals Zepar taught her about parallel worlds. She eventually learned of another version of herself, who acquired the Moon Cell in the Far Side of the Moon. Impressed by this version of Kiara, Zepar linked the two Kiaras together. Passionlip realizes Zepar used Kiara as a catalyst to give SE.RA.PH form. She reveals Kiara swallowed BB, Meltlilith, and her back in the Moon world. Since Kiara served as the basis of SE.RA.PH, Meltlilith and Passionlip were salvaged from her to become Sentinels. Kiara explains Zepar lacked the means to run SE.RA.PH, so she had rely on the Alter Egos and BB, who had hacked SE.RA.PH from the Far Side of the Moon. Suzuka demands to know where Zepar is now, and how many Servants and Masters she consumed since she and SE.RA.PH are one. Kiara answers she lost count at seventy or so, which makes the group see her as the monster she truly is. Suzuka and Cat attack her with their Noble Phantasm when SE.RA.PH cracks the seabed. Passionlip explains it will continue to sink until it reaches the Earth's core, and once it arrives, Kiara will become one with the planet. Kiara proclaims that doing so she can bring salvation to the people. Before that however, she easily kills everyone except Ritsuka when they try to fight her. She tries to consume Ritsuka, but they're saved when BB rayshifts them.

In a flashback, it revealed Zepar used Kiara to effectively gain control of Seraphix while learning much of human pleasure during that time. Even though such a thing is useless to a Demon God, he found himself asking Kiara to help him understand. He recalls Kiara inciting chaos among the Seraphix staff after he transformed Seraphix into SE.RA.PH. Even though he only wanted a place to hide, it instead became like hell to his horror. Zepar recalls further how Kiara seduced the personnel to open the planetarium, and BB and the 128 Servants were summoned. Kiara took control and ruled SE.RA.PH from the behind the scenes all the while claiming she was doing it for Zepar. It was at this point Zepar realized that Kiara has overtaken him. He recalls telling her of the four Demon God survivors' plans to create Singularities to achieve their own separate goal. She refused to create a Singularity, instead opting to become one. That is when Zepar realized the uncontrollable nature of human desire, and tried to unsuccessfully to separate himself from Kiara. He recalls how Kiara only permitted him to reside in her pinky finger while pleading with her to let him free. Eventually though, Kiara releases him from her pinky, and he quickly fades away afterwards. Kiara then ordered BB to start the Grail War to keep her entertainment while SE.RA.PH falls.

Ritsuka find themselves in an old classroom along with everyone else. BB reveals she reversed time to undo the deaths of Suzuka, Tristan, Robin, and Cat. She explains a time leap of approximately three hours is possible in the digital world if it's within a Quantum Time-Lock. The right coordinates also needed, which is the purpose of the class that's located approximately hundred meters above SE.RA.PH. BB explains further that SE.RA.PH digitized the Mariana Trench as it passed through it. Thus, under these circumstances, the higher they go, the further they go back in time. Tristan wonders if it's possible to return to time before Ritsuka's arrival if they were return to the surface. BB replies that it is theoretically possible if they had the right coordinates. The problem though is escaping Kiara's sexual allure, which is acting like a gravitational field. BB explains the group would need exceed to the speed of light to escape, and while possible in the digital world, they would be destroyed in the process. She then reveals she was summoned to stop Kiara's plan, and that Kiara forced her to manage SE.RA.PH until now with the Grail War's conclusion. After Robin asks Beast III is, BB reveals Kiara is only one of half of Beast III, "R". She continues that she learned some Beasts come in pairs like ying and yang, and reveals Kiara is becoming the R of Beast III. She reveals further that Kiara used SE.RA.PH to become a Beast, but she's also still bound to it. The group then prepare to fight Kiara to prevent her from fusing with the planet.

The group arrive back at the planetarium to destroy Kiara. But before that though, Meltlilith asks her why she decided to become a Beast. Kiara answers it was because she was jealous of delight she felt from Zepar's memories of the Battle at Time Temple. After revealing she wishes to worshipped as a god of pleasure, she tries to convert the group into her followers. It is negated however by BB's secret weapon which counteracts the erotic magical energy in SE.RA.PH for the next five minutes. Kiara then decides to destroy the group more directly. The group are able to defeat her, but the area fades away. SE.RA.PH's gravitational field weakens, so everyone begins to float. Passionlip states SE.RA.PH is accelerating, and that she also senses Demon Gods. Kiara boasts of her victory, but Meltlilith reveals she knew she would banish them from SE.RA.PH. She points out that disabling SE.RA.PH's gravitational field has left it defenseless. At Meltlilith's request, Ritsuka uses their remaining Command Spells on her and Passionlip to give them a boost of magical energy. Meltlilith then has BB transport everyone expect her and Passionlip to safety.

Meanwhile at BB's studio, she warns SE.RA.PH's descent is accelerating, and an innumerable number of Demon Gods are trying overflow out from it. She explains that as SE.RA.PH rapidly expands, it will unleash a rain of Demon Gods upon the sea. She's doing her best to halt SE.RA.PH's expansion, but she lacks the processing power to do it alone. She says they needs someone with Moon Cell processing power, which is when Suzuka offers to help.

It is revealed in a flashback that Meltlilith and Passionlip previously failed to destroy Kiara. After injuring Meltlilith's arms, Kiara killed a different version of Ritsuka as punishment for defying her. She also stopped BB's time leap due to part of her still existing inside of Meltlilith and Passionlip, their Karmaphages. Meltlilith vows to redo everything, and help Ritsuka instead to free the Sentinels of Kiara's influence. Passionlip uses Virgin Laser - Palladion to launch her upwards at speeds exceeding the speed of light so she travel back in time. Meltlitlith visits a past version of herself in the chapel, and shares her memories with her. In order to prevent Kiara from realizing the truth, the past Meltlilith committed suicide, leaving only a broken ceramic figure.

Passionlip uses Virgin Laser - Palladion to launch Meltlilith at Kiara. Meltlilith crashes into Kiara, crushing her heart. As her body begins to crumble away, Kiara turns her hair into Demon Gods to grab Meltlilith in an effort to possess her. Her effort is made in vain though as a EMIYA Alter destroys the Demon Gods entangling Meltlilith. He then puts a cable around Meltlilith's waist and has her pulled up to safety. Soon afterwards, Kiara's body crumbles away completely.

Ritsuka wakes up in BB's studio, and they ask what happened to Meltlilith and Tristan. It is then revealed Tristan was the one who pulled Meltlilith up. EMIYA Alter also disappeared, having used the last of his strength to save her. However because her Spirit Origin was too damaged with the second use of Virgin Laser - Palladion, Meltlilith begins to disappear. BB warns her that because she and Passionlip were born from Kiara, they will disappear forever since Moon Cell will not record them. She reveals though she knows a way to register irregulars into actual Servants. She continues she intended to use that method to stay. She also reveals the Moon Cell sent her on a mission to stop Kiara, and she was instructed to disappear upon its mission. She offers to save Meltlilith's Spirit Core as cube and reuse as a Servant to help humanity. Once that process is done, Meltlilith can be summoned as a Heroic Spirit that is essentially a new her while the current her will cease to exist. Meltlilth accepts, and disappears with the promise Ritsuka meet her again. With the destruction of Kiara, the Servants are released, and BB rayshifts Ritsuka back to Chaldea. They arrived back, but Da Vinci tells them Seraphix was dismantled at the beginning of the year, which makes think what transpired was a dream. However on their way to their room, they run into BB. She reveals what transpired was processed as a void phenomenon. She then decides to join Chaldea to repay Ritsuka for their help.

Some time later, Ritsuka is sent back to SE.RA.PH by BB to help her save the world. They are then contacted by different version of BB, who congratulates them on their victory over Kiara. She reveals herself to be BB/GO, and that she has taken full control of SE.RA.PH. She then tells her plan to patch SE.RA.PH into the internet, and use Earth's factories to mass-produce BBB robots to conquer and imprison humanity. After her robot capture humanity, she'll use their brains as bio-processors, then connect their minds to SE.RA.PH so they can all worship her. She reveals she was salvaged from Kiara, and BB is a copy of the original sent from the Moon. She continues she'll use the slot machine BB used to mess with Ritsuka and the others, which was actually used to keep Kiara in check. She then reveals she captured Nero, EMIYA, and Tamamo, and turned them into Sentinels. She explains Ritsuka will need to defeat them to unlock the central area where she is. After BB/GO ends her transmission, BB explains she sent by the Moon Cell to prevent Kiara's transformation into Beast III. She continues that during the Moon Holy Grail War, Kiara absorbed Meltlilith, Passionlip, and BB. After becoming a god of pleasure, Kiara salvaged them from herself to serve her. While Meltlilth and Passionlip rebelled, BB redefined herself as BB/Go, and pretended to be loyal. BB then reveals she was asked by BB/GO to manage SE.RA.PH while she hides at its bottom until she regains to strength needed to defeat Kiara. She also reveals she knew BB/GO would conquer SE.RA.PH once Kiara was defeated. Some time afterwards, Ritsuka free Nero, EMIYA, and Tamamo from BB/GO's influence. Everyone then goes to the central area, and defeat BB/GO. After she merges with BB, they all return to Chaldea.

Participants
Servants

Non-Servants