Okeanos Singularity

Okeanos: The Four Sealed Seas of the End (封鎖終局四海), alternatively The Navigator of the Storm (嵐の航海者), was the third of the seven primary Singularities in the Human Order Incineration Incident. Located in A.D. 1573, it's Humanity Foundation Value was A.

Setting
The Singularity occurred in 1573 within an endless ocean. Before the arrival of Chaldea, Francis Drake went on a seven day voyage, at the end of which she found Atlantis along with its god, Poseidon. Poseidon attempted to destroy the world but was stopped by Drake, which caused the real Holy Grail held by Poseidon to recognize her as its owner. However, another Holy Grail was placed into the era, and entered into a contention with the real Holy Grail that resulted in the creation of an endless ocean.

Meanwhile, David was the first Servant to be summoned into era, and sometime afterwards the Argonauts, Hector, and Blackbeard were summoned. Medea encountered a magus, who after beating her, instructed her to tell Jason that sacrificing a god to the Ark will make him all-powerful. After being told this, Jason told the other Argonauts to find a god to sacrifice, but Atalanta refused and left. Hector encountered Blackbeard and gave him the Holy Grail, which he used to summon a crew of Servants. Discovering Blackbeard's obsession with Euryale, Hector joined his crew as a double agent until Euryale was found. In the meantime, Atalanta found David and told him what Jason planned to do with the Ark. Learning of this, David decided to wait with Atalanta until allies could arrive in the era.

History
Ritsuka and Mash arrive in the Singularity on a pirate ship and subsequently defeat the attacking crew. A crew member explains their ship had suddenly appeared in the ocean, with their maps and compasses being useless. He suggests they go to a nearby pirate island to replenish their supplies and get clues on the whole situation. After subduing the pirates that attacked them when they came ashore, the pair are led to Francis Drake’s secret hideout. She agrees to speak with them, but only if they best her in combat. After she is defeated, Drake joins Ritsuka and Mash alongside her crew, and throws a feast to celebrate. During the celebration, she explains that the ocean is endless and contains islands of wildly different climates. The bizarre winds and current also make sailing very difficult. Drake reveals she was planning to sail out to find a home base for her and her crew tomorrow before Ritsuka and Mash arrived. Mash notices she has a Holy Grail, previously used to create endless food and drink, when Drake offers Ritsuka a drink in friendship. A crew member recalls Drake received it by defeating Poseidon in Atlantis at the end of a seven-day voyage. Mash realizes the Grail chose Drake as its owner when she prevented Poseidon from flooding the world and destroying civilization. After defeating some rowdy pirates, Drake gives the Grail to Mash. The Singularity remains unresolved however, Romani Archaman realizes the Grail they received is the real one existing in the era. He also deduces the endless ocean resulted from the contention between the Grail placed to disrupt the era and the real one. Ritsuka and Mash ask for Drake’s help in receiving the other Grail and restoring the era. Given back the Grail, Drake is convinced by Leonardo da Vinci and Romani to help.

The next day, the group sails out when they’re attacked by pirates, who are actually only conceptual beings of the average pirate. They eventually land on an island where they fight more pirates and Eric Bloodaxe while exploring its jungle. After defeating him, Drake soon finds a viking ship. Inside she finds the ship’s sea chart, which details the island and the surrounding ones. Returning to the ship, the group sail to an island in the northwest according to the chart. Reaching their destination, the group proceed to a Leyline and set up summoning circle there. Romani tries report his findings on the pirate flag they retrieved early, but communications are quickly cut off. Concerned for her ship, the Golden Hind, after an earthquake, Drake and others return to the shore to check on it. A crew member tells her the ship won’t move. Ritsuka and Mash suspect a bounded field around the island is responsible. The group then search for the bounded field’s source to remove it so they can sail again. Eventually they find and enter a labyrinth where they fight Asterios. However, when Drake prepares to finish him, a female Servant pleads with her to spare his life. Revealing herself as Euryale, she believed the group was attempting to capture her. After Mash tells her of their situation, Eurayle reveals Asterios set up the bounded field to prevent outside enemies from entering. Agreeing to remove it, she and Asterios join the group.

After Asterios removes the Bounded Field, the group leave the island. While sailing, Euryale reveals that a perverted pirate Servant is after her. The group eventually encounter Blackbeard‘s ship, Queen Anne’s Revenge which has been chasing Drake’s ship. As the two ships clash, Blackbeard orders Eric to seize the Grail from Drake while he captures Euryale. The Golden Hind cannot penetrate the Queen Anne’s armor though. Blackbeard and Eric board Drake’s ship. Revealed to be a Servant of Blackbeard, Eric tries to capture Euryale, but he is defeated by Ritsuka and Mash. After he disappears, Mash blocks an attack from another Servant meant for Ritsuka. The group then retreat after Drake shoots down the ropes attaching the two ships. Unfortunately, Anne Bonny blasts a hole in the ship, but Asterios carries it despite his injuries.

Carried to a nearby island, the group head to a forest to get wood to repair the ship. While travelling there, Romani suspect the Queen Anne’s Revenge, is Blackbeard’s Noble Phantasm because of the mass reading of magical energy. He also says the Golden Hind showed the same reading, though he attributes this to the Grail. He realizes Blackbeard’s ship is his Noble Phantasm, which strengthens depending on the size of its crew. He also reveals the ship’s magical energy weakened when Eric was killed. The group resolve to kill the rest of Blackbeard’s create to further weaken his ship. After slaying some wyverns, Mash gets the idea to use their scales to repair the Golden Hind. Da Vinci informs them they’ll need thirty more wyverns, so the group go off to find a nest. While searching for a nest, they hear someone being attacked by wyverns and go off to rescue them. After slaying the wyverns, the group find a small and strange bear creature along with an angry female Servant. Once she calms down, Ritsuka and Mash tell her and the bear creature about Chaldea’s mission and the nature of the Singularity. She reveals herself to be Artemis and that the bear creature is Orion. The pair then help the group raid a wyvern nest, where they finally retrieve enough scales to repair the ship.

After repairing the ship, and equipping it with a ram, the group set sail, joined by Artemis and Orion. As they to enter unknown waters, the group discuss on how to deal with the Queen Anne’s Revenge. Drake suggests ramming them while Euryale suggests assaulting them with arrows. Artemis suggests someone can board the ship and cause chaos before the ships collide. She reveals that since she was technically summoned as Orion, she can use his power of walking on water, as he is Poseidon’s son. The group eventually confront Blackbeard’s ship and execute their strategy. While the ship charges towards his ship, Euryale pelts Blackbeard’s crew with her arrows while Ritsuka and Mash deal with boarders. Artemis boards his ship and fights the crew while Orion sabotages their ammo supply. After his ship’s ammo supply is destroyed, Blackbeard attempts to retreat when the Golden Hind rams into his ship. Boarding his ship, the group defeat Anne Bonny and Mary Read. After Blackbeard is defeated, Hector betrays and fatally wounds him, and steals the Grail from him. He expresses his frustration at Drake disrupting his plans to destroy the era by giving the Grail to an idiot. The group tries to catch him, but he boards the Golden Hind to kidnap Euryale. Asterios tries to save her, but he’s wounded in the battle. After Blackbeard fails to shoot him, Hector boards another ship with Euryale. With the Grail now gone, Blackbeard’s crew disappears, with Blackbeard and his ship following soon after.

As they pursue Hector, the group discuss his plans for Euryale and the Grail when they encounter a storm. Using its tailwind, they eventually catch up to Hector after dealing with a ghost ship. Ritsuka, Mash, and Asterios then board his ship to rescue Euryale. As they continue to battle, another ship moves towards their position. Drake fires her cannons at it but they’re all deflected. Hector escapes to the other ship, and Artemis recognizes it as the ​Argo​. Jason demands the group hand over Euryale to him, otherwise he’ll send Heracles to attack them. They refuse, so he sends both Medea and Heracles to kill them and steal Euryale. Medea sends waves of Dragon Tooth Warriors to attack the group, later joining the fight herself. Her combat skills are subpar though, so she switches out with Heracles. The group are unable to defeat him however because of his Noble Phantasm, God Hand. He suddenly attacks Euryale, whose death would foil Jason’s plan, but Asterios protects her. As this is happening, Jason orders Medea to retrieve Eurayle, but Drake and Mash protect her. Hector then unleashes Durindana Pilum, impaling both Asterios and Heracles. Jason commands Heracles to bring Euryale to him, but Asterios plummets him and himself into the ocean after thanking the group. They use this opportunity to retreat from the Argo.

After retreating, the group discuss the Ark that Jason mentioned earlier. Romani explains it contained the ​Ten Commandments​ that Moses received from God. He is confused by Jason’s motives for it though since it punishes all who open it. He further explains that the divine punishment unleashed by the Ark’s opening will also destroy the surrounding area. Despite that though, the group go to find the Ark before Jason. As they search island after island for the Ark, the group receive a message attached to an arrow from someone Artemis knows. They land on a nearby island to meet the letter’s sender. After they slay some monsters, the sender asks the group if they’re friends or foes of Jason. To her delight, Ritsuka answers they’re foes, so she reveals herself. Mash recognizes her as Atalanta, and introduces her to the others. Atalanta reveals the Ark is a Noble Phantasm and its owner was the first Servant summoned in the Singularity. Another Servant then arrives, and Atalanta introduces him as David, the owner of the Ark.

After killing some monsters with the group, David calls the Ark is a third-rate Noble Phantasm that only kills whoever touches it. He explains it is summoned independent from him and reveals it’ll remain in the world after he’s gone if someone possesses it. He reveals he heard of Jason’s search for the Ark from Atalanta, and they waited together for allies to arrive. Atalanta explains she was summoned as part of the Argonauts but she didn’t join Jason’s search for the Ark, something he believes will make him a true king. David then reveals that if Eurayle, a Divine Spirit, were to be sacrificed to the Ark, it would destroy the era. He continues sacrificing a god to the Ark would normally only destroy the surrounding area. However that destruction would increase within the Singularity, destroying one of the Foundations of Humanity without waiting for it to collapse. After questioning Jason’s reasons, the group discuss on how to defeat Heracles. David suggest they trick Heracles into touching the Ark to will destroy him. The issue comes with that plan however is that even a Berserker would avoid touching such a dangerous Noble Phantasm. Since it would be disadvantageous to fight all three, Mash suggests they lure Heracles away from Hector and Medea. Orion suggests they hold up somewhere, but Atalanta says no structure on the island could withstand Heracles. Ritsuka then gives their plan on how to defeat Heracles, which everyone agrees with despite the risks.

Following Ritsuka’s plan, the allied Archers launch their Noble Phantasms at Jason, who had just arrived at the island. Jason orders Hector to protect him and Heracles to kill the Archers. However, Heracles makes killing Eurayle a priority, so she and Ritsuka run from him while their allies protect them along the way. They eventually lure him to where the Ark is being held, but he keeps his distance from it. Fortunately, the others arrive and defeat him in battle. They then push Heracles into the Ark, draining him of his magical energy unto his death. With Heracles now gone, the group, now joined by Atalanta and David, board the Golden Hind to chase Jason.

As the group chase after Jason, the allied Archers fire upon the Argon while Drakes unleashes cannon fire. When they finally catch up with him, Jason uses the Grail to summon a Shadow Servant to attack the group. After it is defeated, Jason orders Hector to kill the group while Medea protects him. After he is defeated, Hector attempts to kill Eurayle, but she finishes him off with Eye of the Euryale as revenge for Asterios. David asks Jason who gave him the idea to sacrifice Eurayle to the Ark since doing so would destroy the world. He asks him if either Hector or Medea convinced him that sacrificing a Divine Spirit would grant him infinite power. Confused by this, Jason asks Medea if David is lying, saying that someone him told that sacrificing a Divine Spirit to the Ark would grant him power and invincibility. Medea answers the world’s destruction would technically make him invincible. Angered at being deceived, Jason states how he could finally create an ideal nation, a true utopia. Medea refutes his intentions, and tells him he’ll never be an ideal king because his soul is hopelessly twisted. Infuriated by her words, Jason demands to know how he’s unqualified to be king since he built the Argo and gathered a crew of heroes. Medea then uses the Grail to incarnate him into Forneus, claiming it as her way of protecting him. While the others are doubtful of their victory, Drake inspires them to fight while commanding her crew to hide in the cabins.

After Forneus and Medea are defeated, Jason is returned to normal and demands Medea heal him. However, she cannot heal him as she herself will soon perish. Medea reveals she possesses memories of him deceiving and betraying her despite her adoration. She calls him both cruel and innocent, and states that despite being weak, he attracts others to loyally serve him. She continues that since he betrays too quickly, it would be better for him to sink with the world to avoid any betrayal. After Jason disappears in a rage, Medea regrets not being able to protect him from someone. As she disappears, Medea refuses to answer Ritsuka’s question about the mastermind behind the incineration of humanity since a mage greater than her defeated her. She further tells them to prepare themselves against the mage and to gather more allies. After Medea disappears, Mash retrieves the Grail. As Singularity collapses, Ritsuka and Mash’s allied Servants say their goodbyes before disappearing. However before David disappears, Mash asks him if Forneus was truly a Demon God as Romani claims they don’t exist. David asks Romani about his reasoning, and Romani answers Solomon couldn’t summon such hideous creatures. He wonders aloud how such a powerful mage like Solomon could command such monsters or even plot to destroy humanity. David calls his son a cruel, vulgar good-for-nothing who would plot humanity’s destruction. He apologizes for his words and admits he has little to do with his son. He claims Solomon wouldn’t honestly consider destroying humanity unless he suffered a major betrayal before disappearing. Romani is disappointed they couldn’t gain any more information about the Demon Gods and to know that Solomon is involved with the Incineration of Humanity. After Romani thanks her, Drake is disappointed she will lose her memories of Ritsuka and Mash once history is corrected. She tells Mash that all humans have a dream or wish to want fulfilled, saying all humans perform good and evil deeds to reach their desires even if they don’t know it. She continues to tells her she is better off not knowing her own wish as she’ll know it in the end. After expressing her libertarian approach to life, Drake says goodbye to Ritsuka and Mash before they return to Chaldea.

Participants
Non-Servants