Roa was originally a priest of the Church who quickly rose to the top by utilizing all his father's inheritance. He created the "burial class", the base of today's Burial Agency, along with Narbareck. With nothing left of his resources, he decided to leave the Church, and gave the Agency to Narbareck. After betraying the Church to the Mage's Association, he was left uncredited, and Riesbyfe Stridberg was surprised to hear about his involvement with it. He wished to realize an immortality different from that of Dead Apostles, but, trying to overcome his limits as a mere human, he reluctantly became a vampire in order to continue his research. When considering a way to become a Dead Apostle, his heart was snatched the instant he put his eyes on Arcueid Brunestud, and without noticing it himself, his plan went out of control thereafter. He never noticed that he genuinely fell in love with her, but instead started hating her after it caused him to lose his innocence and turn away from his research.
When she became weak to her vampiric impulse for the first time in the castle, he tricked her into drinking his blood by creeping up behind her, trying to seduce her with sweet words and asked "Are you in pain?" She sucked his blood right there, and he died immediately. After being brought back to life, he became distant from her, not once speaking after that point, and only met later to finish everything. He became a powerful Dead Apostle upon his revival. Taking the forces of the Dead Apostle Ancestors that had then been sealed by the Church, he quickly rose in power amongst the twenty-seven. He earned himself the scorn of the other Dead Apostles Ancestors as he built up power, and eventually Altrouge Brunestud was left in charge of punishing the upstart newcomer. He proved more powerful in battle, reflecting the magnitude of the power gained from Arcueid at her peak and his exceptional quality as a magi, and defeated her without killing her. The rest of the Ancestors decided to reject him and ignore his existence after that point, and, years later, he was eventually destroyed by Arcueid who had joined forces with the Church. Over the next seven hundred years, he reincarnated fifteen times, and he was endlessly killed by Arcueid each time.
Roa's seventeenth incarnation, Elesia, later known as Ciel, was born in 1976 to a baker's family in a remote village in France one hundred years after his sixteenth incarnation died. The sixteenth was destroyed by Arcueid before he had a chance to find a family bloodline with both wealth and power. He could only fulfill the requirement that his next incarnation would have physical potential, so he was born into a normal family without any social standing. In exchange, her body instead had extremely high magical potential, which is the closest in power to his original body in all of his incarnations. He began manifesting on her sixteenth birthday, and greatly enjoyed the amount of power the body gave him. Even though he would have to take a long period of time to take over the town without status, he was fine with waiting until later to obtain social standing. He committed various atrocities to the citizens as he used his new powers to slowly take over the town. After the town was completely under his control, he was inevitably hunted down by Arcueid, who managed to find him after two days of searching. He was killed, and Elesia's body was taken by the Church. She eventually revived with her original personality without any of Roa's influence, while Roa moved on to his next incarnation. He managed to plan his eighteenth incarnation, and choose the Tohno bloodline with a proper amount of wealth and power. Choosing the Far East for his seventeenth revival was on a whim which was possibly just him wishing for a change of scenery compared to where his previous incarnations were born.
SHIKI Tohno, different than the protagonist of Tsukihime, Shiki Tohno, is Roa's eighteenth incarnation. He is the true son of the Tohno family, who was feared by his sister Akiha due to his unstable demon blood, and good friends with his adopted brother from the Nanaya clan. The three would often play with together, and they especially enjoyed playing a game where they would mark territory inside the mansion by carving their names walls, floors, and pillars. He eventually fell to his Inversion Impulse, resulting in him attacking his sister. She was protected by Shiki, who suffered from a nearly fatal wound and having part of his "life" stolen by SHIKI. As with the traditions of the Tohno household, SHIKI was to be killed by his father, Makihisa Tohno, but he managed to revive using Shiki's "life." He regained a measure of his sanity, so Makihisa was unsure about killing him. While he was officially declared deceased to the rest of the family and officially replaced by Shiki, he was kept locked in the Tohno Mansion's cellar. Makihisa planned to bring him back into the family after he healed, but he remained locked up for around eight years. After Makihisa's death, he was taken care of by Kohaku, who planned to use him in her revenge against the family. He is eventually released before the start of Tsukihime.
It seems Roa was popular as a virtuous man when he was a priest up until his betrayal. He seems to have great dislike for the Church, commenting that the already ruined Church has degraded even further in eight hundred years, but also says the existence of a woman like Riesbyfe makes it not quite as bad. He had some form of a close relationship with Nabareck, as, while she did not want to leave the Church or live with Roa, she was willing to pass on the information to her child to ignore a newcomer Dead Apostle in one hundred years.
He is an acquaintance with Nrvnqsr Chaos, and they are close enough to call each other friends. Nrvnqsr believes that he understands Roa more than the other Ancestors, having talked extensively about their own meanings of eternity and Roa having taught him the "Soil of Genesis" with the idea of having him use it to capture Arcueid. While they are both heretics by the standards of vampires, Nrvnqsr states that each case is isolated, and that doesn't mean that they understand each other on that point. Like the rest of the Ancestors, this causes him not accept Roa as one of them. When they meet again in Actress Again, Nrvnqsr remarks that the "name of the archangel has fallen indeed" after Roa calls him "pal." While he has become cruder than in the past, Nrvnqsr finds his incarnation as SHIKI is the worst. He compares his gradual assimilation with chaos with Roa's constantly diluting ego, and comments that it may be the last time they trade words. While Roa found perfecting the “Soil of Genesis” to be fun, and that the idea of working together on cooperative research is appealing, they decided to simply crush each other following their natural destructive urges.
During comedic scenes of Melty Blood, characters berate him for attempting to act important whenever he act serious. He is considered part of the Back Alley Alliance along with Satsuki Yumizuka, Sion Eltnam Atlasia, Riesbyfe, and White Len. White Len mentions that he is even at the bottom of that group. Kohaku keeps calling him "Mr. Nero" and "Mr. Neroa" in order to infuriate him during his time in the limelight. He tries to assert that while others may not know him, that she should at least recognize him as SHIKI, but she comments that the SHIKI she knew didn't look like some pianist.
Ever since he was born, he had no interest in anything in particular, feeling more mechanical than human. His first feelings were those of pity rather than anger or despair. He simply thought everything around him was pitiful, and he himself was the most pitiful of all. He saw life which breaks down, daily life which fades, and time which is forgotten, all without limit. Everyone falls, but they still continue to struggle desperately to continue existing. When they judge that it is not possible to continue existing, they continue to reproduce instead, but even that dies in the end. He found that there is no recompensation, not for those who die, as they had no hope even in the beginning, but rather the noble wish and yearning for eternity which everyone longs for yet can not achieve. The constant repetition of wishes is nearly impossible to measure, so he wished to replace the almost-comical cycle with one pure thing. Living for one reason, which could not be termed as a "conviction", he sought the first word that he happened to learn, "eternity." He believed the prospect of eternity is the only goal worthy of effort. He had no interest in that which breaks down, and wished to see and understand death so that he could take a bit of interest in it.
While those seeking eternity often become Dead Apostles in pursuit of that goal, it was simply a means of furthering his own goal for Roa. He believes nothing in existence has yet to reach the level of immortality, something which would define eternity. When something has shape, it cannot help but perish. All living things internalize death the moment they are born. Something without death within them is probably something that never existed in the first place. Human vessels cannot resist wearing down mentally and physically with time, and they do not have the capability to last one thousand years. Even the body of a vampire does nothing to stop the aging of the mind, requires stealing from others to exist, and their supplemental parts have to be from the same species, humans in general, meaning that they are not versatile. He calls their process degeneration rather than evolution, and refers to them as a species that ages slower and dies harder rather than any sort of embodiment of eternity. That which cannot function independently in perpetuity cannot be called eternal, so depending on others to halt their aging makes it presumptuous to call them immortal. The only thing becoming a Dead Apostle allowed was the ability to realize his goal with time which his human body would not allow.
While aging can be stopped, that is only halting it, and a stopped mind has no meaning. Creatures that can function independently in perpetuity in a state close to perfection exist, such as beings like jellyfish that can feed on themselves and multiply, turning old cells into nutrients to produce new cells. They have no such thing as a lifespan, but they can only be called perpetual because the have no intelligence. Eternity without having intelligence is no different than gaining eternity by death. Even with a body unable to age, as long as something exists, it cannot escape death. The only way to truly escape death is to die, creating a contradiction that cannot be solved. There cannot be anything in the world that cannot die. He instead concluded that preserving his existence after death is what would make him truly immortal.
Becoming eternal by living as a human with immortality is impossible, as long years will destroy the body and wear away the flexibility of the mind. He had no interest in such a stained immortality, as persistently maintaining individuality makes eternity unattainable. Rather than seeking immortality as a single human, he sought to choose an infinity where he exists eternally. In order to preserve the purity of his essence, he devised his method of reincarnation to restart from birth, exist as himself, and then die once more. The cycle would preserve the purity of himself throughout the generations. He realized eternal reincarnation far better than anyone else, but it still requires new unborn children other than himself to continue. While he would lose his eternity with the extinction of the human race, he believes that "eternity exists only as long as there is an observer." If no humans existed, he would not be able to confirm himself, which would make continuing to live useless and bring his immortality to an end. While Nrvnqsr Chaos believes that this theory is far from a true thesis of eternity, Roa believes that if everything comes to perish, then it should perish. Once observers cease to exist, everything will become unchanging. His eternity is temporary until such a time occurs. As he cannot turn everything into nothingness, he wishes act as an observer and live until then.
Upon seeing Arcueid for the first time, he instantly fell in love with her, having such a feeling for the first and only time in his entire life. Though it was only an instant, he lost his purity the moment his heart was stolen by her. She was someone not aware of own her self, who was only treated as a method of killing. He viewed her during her brief respite between killing her enemies and returning to sleep that she cannot wake from herself. As she gazed at the moon with distant eyes while not even knowing her own fate, he saw her as the embodiment of the eternity he seeks. He was so pure that he was unable to understand his own emotions, so he misconstrued the act of thinking about someone else so much it almost made him go crazy as his first feelings of hatred in his life. She changed him, and while she didn't change his fundamental goal of attaining eternity, she degraded it from seeking eternity for no reason, a pure, undefiled will, into a means to an end of eternally reaching out for her. While he understood this about himself, he could not do anything to change his heart. He regretted having lost his original purity because now, like all the other pitiful wretches, he wished to continue existing as himself as he was right then.
Roa as an individual has ceased to exist, and the part of his soul left over can only be called the conceptualization of Roa's desire for immortality. He considered one's ego as unnecessary, so he doesn't really care what he does as long as he can continue his thesis on immortality. That first image of Arcueid is the only remaining emotion in Roa's heart after eight hundred years and seventeen reincarnations. While his personality has long died out, it is an eternal memory burned into his soul that continues to exist without disappearing. This memory made him hate the True Ancestor that caused his purity to fall, her existence, and everything about her. The hatred guided him trick her, become a Dead Apostle, steal her power, and wait for her to come to him. It has caused him to reincarnate so many times, just so that he can wait for her to come pursue him every time. Shiki believes that he wouldn't have made such mistakes if he was simply told that he was feeling love.
Once he starts to possess Shiki, he has no direct control. He only acts as a voice inside Shiki's head, but it often devolves into repeating nonsense as it urges him to act. When confronting Ciel, he repeats "Slice her apart" numerous times until Shiki uses his willpower to silence him.
Roa is the main antagonist of the "Near-Side Moon" routes, the stories of Arcueid and Ciel, of Tsukihime. His will has completely taken over during these paths, and he sets out to follow his usual goal of building his power as a Dead Apostle to lure Arcueid to him.
After slashing Arcueid in 17 pieces, she convinces him to help her in taking down Roa, who Arcueid has been targeting. Roa doesn't make an appearance until after Nrvnqsr's death. Shiki initially believes that the end of the city's vampire had come with the defeat of Nrvnqsr, but he learns that the vampire Arcueid was hunting was someone completely different. Nrvnqsr was a completely separate vampire with the sole purpose of hunting her, while the original vampire that she came to find is still active. He learns small pieces of Roa's identity, but not of his true connection to Arcueid.
Roa makes contact with Shiki after he parts with Arcueid during the night three days after Nrvnqsr's death. He engages Shiki with a knife, but he is left on the defensive until Shiki becomes distracted by his disoriented memories being brought back by SHIKI's face. Ciel eventually interrupts the fight by piercing Roa with three Black Keys and engulfing him in flames. Still silently cursing Shiki with his gaze, he is forced to retreat due to the attack.
After Arcueid nearly sucks Shiki's blood due to her vampiric impulses, she attempts to take out Roa by herself and is apparently killed in the process. Enraged and in grief, Shiki proceeds to destroy the walkway he and Roa are on as a distraction and utterly destroys Roa's point, thus nullifying his very existence and preventing him from ever reincarnating.
Due to the alterations to his memory by Makihisa, Shiki has completely forgotten about SHIKI's existence. Shiki eventually starts to believe that he may have been the one to do the killings in town. Due to this, Ciel believes he is a very likely candidate for Roa's host, as all records of SHIKI have been removed in favor of portraying Shiki as the true son of the Tohno family. She interacts with him to determine if he has any relation to the recent incidents.
With the help of Ciel, Shiki successfully defeats Roa. However, he transfers the burden of his madness to him, causing Shiki to have murdering thoughts and strange dreams (one of which Shiki finds about Ciel's past before and after being possessed by Roa).
In Ciel's True Ending, Shiki, realizing that Roa has overtook his body, tries to kill himself by slashing his throat, so Arcueid won’t have to finish him.
In Ciel's Good Ending. Ciel believes that if Shiki kills Arcueid, Roa might get weaker. As both girls discuss how to get rid of Roa, he overtakes Shiki's body. In order to stop it, Shiki slashes his chest in order to kill himself and stop Roa. After that, he has a vision of Roa before he started reincarnating and vanishes, disappearing for good.
SHIKI Tohno is the main antagonist during the "Far-Side Moon" routes, the stories of Akiha and Hisui. SHIKI's inversion impulse keeps Roa from exerting his will over him, resulting in a very deranged individual obsessed only with getting revenge on Shiki for stealing everything from him. Roa is only alluded to twice in the Far-Side Moon routes: in Akiha's route there a brief mention from SHIKI that there is something in his mind that wants to take over and in Kohaku's route Akiha's inversion at the end of the route is explained as her absorbing an "evil spirit" after killing SHIKI.
Roa in the Tsukihime manga is a mix of both versions of himself from the Far-Side and Near-Side routes. He bears an appearance similar to that of Far-Side route Roa, otherwise known as SHIKI, but contains the abilities, goals and the clothing of Near-side route Roa. He becomes progressively more dangerous each time as he begins utilizing continuously greater feats of Magecraft. During his first three appearances, he is always targeting Shiki so as to take vengeance for his death as SHIKI.
The childhood flashbacks are also more emphasized, showing SHIKI to be a bratty and prankster boy whose only friend was Shiki and was quite prone to have outbursts due to the Tohno blood. He also asked Shiki to kill him in case that he ever inverted, but Shiki refused to kill his friend. When SHIKI inebitably inverted, Shiki not wanting to kill him but also wanting to protect Akiha, decided to shield her with his body at the cost of his life.
After Shiki remembers his childhood, SHIKI attacks him, but Akiha arrives in time. The siblings have a confrontation in which Akiha refuses to acknowledge him as her true brother, causing him to try to kill her. However, Ciel manages to interrupt him just before he kills either Shiki or Akiha. During another confrontation between him and SHIKI, he believes he has successfully killed Shiki and loses it, causing Roa to take full control of his body. Through the use of a Bounded Field, Roa manages to take control of quite literally the entire city of Miyaki's supply of magical energy, directing it all towards his final battle with Arcueid.
Roa and SHIKI are presented as completely separate characters for the first time in this adaptation. In "Crimson Moon" Roa recalls his first fateful meeting with Arcueid. This story shows him in less of an antagonistic light.
Roa makes his first appearance in Melty Blood Actress Again as a playable character. In his own story mode, he is accidentally created by Dust of Osiris using TATARI, and is surprised to find himself alive after being killed by 'that woman'. He then wanders around until he runs into Len, where he apparently kills her and proceeds to use her to call out her 'master'. Shiki then arrives and the scene and after a brief exchange of dialogue, the two fight and Shiki is defeated, though Roa chooses not to kill him completely. After a battle with Ciel, Roa meets Arcueid who tells him that she will kill him once and for all, but disgusted by the fact that Arcueid has come to care for humanity, Roa calls her a 'fake' and fights her until somehow, he manages to awaken the princess-version of Arcueid. She is amused by his efforts and tells him that she will allow him one last 'kiss' before destroying him. Delighted at the sight of the "Eternity" he had witnessed 800 years ago, Roa proceeds, saying that he would gladly burn up his 18th and last cycle just for her.
He also makes appearances in other character's story modes as well, but as mentioned above, he is present as nothing more than a standing joke.
Roa has short appearances in Carnival Phantasm, mainly serving as a joke character.
Roa's incarnation Tarantella appears in the Edmond Dantes Drama CD. In the Drama CD, Roa is still a Dead Apostle who gained his power to reincarnate and acts a one of the antagonist's of the Drama CD. His soul is burned away by Edmond Dantes in battle, possibly implying that Roa of that timeline is unable to reincarnate and is gone forever.
Roa reached his peak as a human, so he sought to become a Dead Apostle to complete his magical theory, the thesis on immortality, and obtain Magic. Normally, the process to become a vampire would have taken at least one hundred years starting from the level of a Ghoul, but Roa wished to greatly speed up that process. When becoming a Dead Apostle by having a True Ancestor suck their blood, the power of the Dead Apostle raises in proportion to the True Ancestor's strength. He used the strongest True Ancestor, Arcueid Brunestud, in order to instantly become the strongest Dead Apostle by skipping the stages of growth with her immense power, and planned to rise to the top of the hierarchy in just ten years. Upon having her take his blood, he stole a large amount of her power, and managed to reach the apex of his magical abilities as he built up his power. Taking the place of a Dead Apostle Ancestor sealed by the Church, he gained their followers and rose in power among the twenty-seven, and managed to defeat Altrouge Brunestud in battle. He was eventually destroyed by Arcueid who had joined forces with the Church, but he had already managed to establish his system of reincarnation. While he is considered as an Ancestor by the Church, and Arcueid considers them to be a group of twenty-eight rather than twenty-seven, he is listed as "Extra" outside of the regular twenty-seven because they consider him to be a heretic who does not uphold the ideals of regular vampires.
Once his will is awakened in a host, he starts off as a weak Dead Apostle, and begins to increase his power by creating The Dead throughout a city like a traditional vampire. Draining the blood of humans, he increases his power bit by bit as more victims are slowly transformed. Due to being born as a human baby with parents, it is impossible to detect him beforehand. He shows no signs of being anything other than human, and only transforms into a vampire upon reaching an age where he can do everything at a satisfactory level. He quickly begins to utilize the relationships he gained until that time to blend perfectly into society, and it is usually only when the entire town is turned to The Dead, the Church is able to finally detect his presence. Due to the fact that he only chooses fine lineages and excellent hosts, it is much easier for Ciel, who has innate knowledge of how Roa works, to find him by searching out the families in the area that meet his criteria. It quickly allowed her to find the bloodline he reincarnated into in Misaki due to the Tohno family being the only old family that meets his criteria.
He only acts one time in total himself to create a Dead, and then controls it in order to create even more to build his power and expand his territory. Of each victim they attack, more than half of the energy goes to him and the chance for another Dead to be born is created. While many are created, a number of bodies fail to awaken, leaving behind victims. During Tsukihime, while there are only ten known victims, the failures, the actual number of Dead number over one hundred. He hides his presence during this period, acting like a queen bee being nourished by the worker bees, to avoid being immediately found by Arcueid or the Church. He also uses various magical techniques to makes things seem not out of the ordinary even with the victims appearing. Due to utilizing only the Dead while he sleeps, it is hard to locate him before his power grows enough to make him a threat. Even if the Dead are targeted to lure him out of hiding, he can just send out a few to collect the minimum amount of blood to survive, making it a long, tedious process for Arcueid to hunt him. After working to build up his power in Tsukihime, Arcueid believes he is around the level of a "Class Five" vampire, but lacks the ability to become as strong as other Ancestors.
The status of being a Dead Apostle is stored within his soul. Those transformed by a True Ancestor don't just have their bodies corrupted, but also forever have their souls spoiled by the bite. Those he takes over return to normal if his influence is removed from them. Ciel, despite acting as Roa for a long duration of time, has no remaining traces of having been a vampire. Shiki, who is slightly taken over by Roa in Ciel's route, slowly gains the advantages of a Dead Apostle, such as strength, speed, and regeneration. After Roa is fully destroyed, his body returns to normal without any traces of having been changed. Arcueid's stolen power is also kept within his soul, and it will not be returned to her unless it is fully destroyed. Even after killing him seventeen times, she is unable to regain it until he is fully destroyed during the Near-Side routes.
When Roa's manages to fully become the dominant force in SHIKI's mind during the Near-Side routes, he takes on the full benefits of being a Dead Apostle created by Arcueid. As a Dead Apostle created by a True Ancestor, being under the full moon greatly increases his power, and it can be said he is practically immortal under such conditions. He already has supreme regeneration from the deepest of wounds, and the effects of the moon only serves to increase it even more. He is able to regenerate his entire body after it is almost entirely destroyed by Arcueid's Marble Phantasm with the exception of his ankles. After the attack, his ankles start running as the rest of his body is regenerated with each step. He says that if the moon were waning even the slightest bit, such regeneration would have been impossible. 
Roa's magecraft is Numerology (数秘術, Sūhijutsu?), which is related to the Kabbalah’s Thaumaturgical Theory. He specializes in lightning based attacks, and most of his abilities involve electrical discharges. He makes use of the spells Set (セット, Setto?), a trap-type spell, Snap (スナップ, Sunappu?), a magic projectile attack that falls under the Single Action-type, and Square (スクウェア, Sukuwea?), a spell that amplifies the power of other spells. As one of the Dead Apostle Ancestors, he possesses a Reality Marble, Overload (オーバーロード（過負荷）, Ōbārōdo (Kafuka)?), which applies the effect of the Square spell to all of his spells while it is activated. Spells inherited by Ciel also show that he has knowledge in High Speed Incantation, Simplified Repetitive Incantation, Suggestion, Church Sacraments, and Necromancy. He has the ability to modify his appearance to suit his own preferences, such as when modifying SHIKI's body when he fully takes control, or briefly taking on his original appearance in Actress Again. During the manga, he creates a complex Bounded Field over Misaki after laying numerous magical seals across the entire town and using the school as the center for his lair. Much like Caster, he uses it to drain magical energy from the land and living organisms of the area, allowing both him and his lair to regenerate with the energy.
He has vast knowledge in other areas as well, such as spells forgotten from the Age of Gods, one of which, Soil of Genesis, he teaches to Nrvnqsr Chaos in the interest of helping him shape the chaos that makes up his existence. Nrvnqsr believes that Roa may have even had been able to find a method to completely control the chaos if he had managed to live, stating that it must have been regretful not being able to fully utilize such a clear heresy before being destroyed. He has great understanding of the True Ancestors and Crimson Moon, making him capable of discussing and analyzing Crimson Moon's methodology and plans for reincarnation with the aspect of him that exists within Arcueid. He states that his own method of reincarnation is more efficient due to the fact that he only requires his base existence remaining intact, while Crimson Moon needs a vessel of the same level to revive. Roa doesn't use any Magecraft within the events of the Tsukihime visual novel due to not yet recovering the proper knowledge to use it. He only makes use of it during his Melty Blood appearance and the Tsukihime manga.
As SHIKI, he is skilled with using a knife in close-quarters combat much like Shiki. He has Mystic Eyes with properties similar to Shiki's Mystic Eyes of Death Perception, and uses them to aim for lines when fighting with his knife. While Roa believes that they are the same Mystic Eyes of Death Perception that Shiki gained from viewing death, they are significantly different. His eyes allow him to see "the point that makes things live", making them more akin to cutting the "life" of a person rather than the "death". He cannot see lines on inanimate objects or destroy them, as it stems from the abilities of the Tohno's bloodline to perceive the "life" of a being and then "plunder" it. The lines seen by the eyes have the same placement as lines of death, allowing Shiki to block Roa's strikes by viewing the lines on his own body to anticipate the target of the cut.
In the Tsukihime manga, Roa utilizes some control over SHIKI Tohno's "Immortality" ability, which allows him to crystallize his blood, which then can be used as an extremely fine sword or thrown weapon.
Roa's method of reincarnation involves him having altered his soul, making him possibly the only person who has succeeded in turning the incalculable and unchangeable soul to a changeable and transmittable information. Normally, the soul scatters and returns to Akasha after leaving the envelope of the body upon death, but Roa's soul is able to be transmitted. It has lost the concept of destruction entirely and morphed so that it can remain conscious even while held within the record. No matter how many times his body is destroyed, he will always revive within a new one after a period of time. While it doesn't simply propagate through the air to take over the body of another, it can be called something similar to an electromagnetic wave. The human brain transmits and receives the soul constantly to ensure his continued existence.
Arcueid only has the ability to kill his body rather than his "meaning", so she has failed to completely destroy him. Only something with the concept of "rejection of reincarnation" like the Seventh Holy Scripture can disperse his soul into nothingness and stop his it from resurrecting, or it must be destroyed completely, such as by having his point of death pierced by a Mystic Eyes of Death Perception user. He cannot truly be called Roa as of his latest incarnations, as his own ego has started to fade away with each reincarnation. He is a malicious conceptualization made up of a steady accumulation of wills, history, and magical knowledge that has little in common with his original self besides his goals. Falling in line with his thoughts on an ego being unnecessary, it might have been part of his objective from the start. Among the Dead Apostles, he is known as the Serpent of Akasha and Ouroboros due to the serpent being the symbol of infinity and cycles. It suited him perfectly as something constantly shedding its skin and gaining a new body. The Church instead records him as The Infinite Reincarnator.
Roa picks each of his vessels beforehand, choosing a balanced mixture of both wealth and magical abilities to ensure his quick ascension to power without attracting attention. Being born into a family of high social standing, property, and money makes it easier to make the whole town into vampires as he pleases. The most important aspect is having special abilities from birth. Magecraft is something that can be learned, but having inborn abilities passed on by blood allows for greater power. He only chooses those with "something not human" in their lineages, such as those called Demonic Children or psychics. With wealth, influence, and inhuman power, he is able to follow his desires each time he awakens. The exact method is unknown, but if he is unable to personally select a family, he can instead define parameters such as "physical potential" to randomly choose his next reincarnation.
He only needs the bloodline itself, allowing for him to set reincarnation process while the vessel is not even born. He can also have two active vessels at one time, such as Elise and SHIKI, allowing him to quickly move to the next without waiting for a long period of time. When the vessel is born, all of the "information" of his self, his soul, is transmitted into the body. The transmigrated soul is stored deep within the baby until it matures or gains enough intelligence of its own succeed "his self." While the person is definitely has the same soul as Roa, they are initially raised as an entirely different person, under a social community, growing up physically and mentally until Roa's intelligence is awakened. The incarnation speaks with whatever dialect the host uses, so in the case of SHIKI, sometimes casual speech such as "pal" is used. He finds the use of different dialogue to be refreshing and part of the fun that comes with a new vessel.
Once awakened, the will of the host no longer truly matters. Whether the environment raised them to be a good or bad person, they instantly start to adhere to Roa's will and become a new vampire that is Roa. It is not the same as two people sharing one body, as the human is considered to be Roa. While Ciel was initially feeling his will, she was disgusted by the thoughts. She gradually fell into its influence, and even began to enjoy the gruesome slaughter of everyone dear to her. His reincarnated will still cannot exist by itself, so there is still the will of the body. His consciousness is still that of his original self, but he can only tell the will of the body "I want to do that."
During every cycle, he was able to retain his consciousness and all the past memories of his previous incarnations. As a consequence, since they all experienced the same things Roa has, their general opinions remained the same. Roa is the one moving the body, but the process of moving it was determined by his mind that had grown along with the body. Ciel was able to guide his will somewhat by making his killing slightly less gruesome, and SHIKI, due to his abnormal personality affecting Roa, causes him to take out his grudge on Shiki before dealing with Arcueid. The full personality is definitely Roa no matter how the person was during their life, displaying Roa's coldhearted, thorough and selfish, yet gentle and intellectual nature. The physical characteristics are based on the body, though he may change some aspects to suit his own preferences.
None of his incarnations have reached his full power because they lack the Circuits of the original, and even though he technically possesses every memory his past incarnations had, he draws these memories only gradually from the Akashic record. He is forced into waiting for the specifics of his former lives to reappear to him. This is the reason why he is unable to use Magecraft during the events of Tsukihime; he simply no longer recalls exactly how to do so and must bide his time till he is able.
In the events his story on Melty Blood Actress Again, he claims to have the potential to become TATARI by taking the blood of Sion.
- ↑ Wait, so Roa was watching her that whoooole time from the shadows? He was a stalker?
Nasu : When Arc was first suffering from the side-effects of vampirism at first in the castle, he crept up behind and asked "Are you in pain?" Trying to seduce her with sweet words. Then Arc sucked his blood. Roa died immediately there. After he was brought back to life, he became distant from Arc, only meeting her again to finish things. But they never even spoke at that point, either.
 Tsukihime Dokuhon PlusPeriod - TSUKIHIME Dictionary: Roa [Person's name • Dead Apostle], p.191
Roa [Person's name • Dead Apostle]
Full name, Michael Roa Valdamjong. A Dead Apostle.
Though the Dead Apostles themselves merely see him as a normal Dead Apostle, the Church counts him among the 27 Dead Apostle Ancestors. Known as the Infinite Reincarnator, he attempted to realize an immortality fundamentally different from that of the other Dead Apostles. Originally he was a priest of the Church, but for the sake of surpassing his limits he had no choice but to become a vampire.
He tricked Arcueid, the strongest True Ancestor at the time, into drinking his blood, and immediately became a powerful Dead Apostle. Then, by unifying the factions of those Dead Apostle Ancestors who had already been sealed by the Church, he established his influence. In response, Altrouge set out to put the newcomer Dead Apostle in his place, but by that time Roa was already powerful enough to defeat her instead. Of course, it was only natural. Not only was Roa an excellent magus in his own right, but he was able to wield the power of the strongest True Ancestor, Arcueid, at the same time.
As a result, the 27 Ancestors left Roa to his own devices. It wasn't until many years later that he was finally defeated by Arcueid and the Church working together. After that, he reincarnated into new hosts a total of seventeen times, locked in a never-ending deathmatch with Arcueid.
Similar to Nrvnqsr, the identity called "Roa" was fading even as he clung to eternity.
Though the Roa that appears in Tsukihime has a rather brutal personality, that's because he's using Tohno Shiki as his base. The original Roa was a calm intellectual.
…Well, he was still cruel and utterly selfish at heart.
He was obsessed by his thesis of eternity and was convinced he needed nothing else. However, the moment he laid eyes on Arcueid he was captivated, even though he should have seen her as nothing more than a tool. After that, Roa's plan spiraled totally out of control… though he himself never noticed.
Kagetsu Tohya - 27 Dead Apostle Ancestors Series, ＥＸ／Michael Roa Valdamjong
Refer to Tsukihime.
One who wanted to achieve the ultimate magic.
- ↑ Arcueid route - 11th Day: The World of the Moon
- ↑ TYPE-MOON Fourth character poll - Overload: Launched when his remaining life is 100. "Square" is cast on all of his sorcery. ---And this other sorcery, "Square" doubles his power of his sorcery, making it equal strength as the EX moves.
 Melty Blood Act Cadenza PS2 Manual - Dictionary: Serpent of Akasha [Term], p.060
Serpent of Akasha [Term]
Another name for Roa -- the “extra” among the 27 Dead Apostle Ancestors, and the magus that established the art of transmigration.
While the common goal of the Dead Apostles is to attain perfect immortality that doesn’t rely on the intake of blood, their paths toward this goal are varied.
One tried to become indestructible by turning his body into formless chaos. Another demonstrated an ineradicable existence by becoming a phenomenon.
As for Roa, he focused on the soul, rather than the body, mastering magecraft that allowed him to transmigrate and assimilate into another individual upon the demise of his physical form.
 Tsukihime Dokuhon PlusPeriod - TSUKIHIME Dictionary: Serpent [Colloquial term], p.188
Serpent [Colloquial term]
Roa's nickname. The Dead Apostles gave it to him, in reference to the way he lives on through reincarnation. Given that he dabbled in alchemy, it's quite fitting.
Of course, when you hear alchemy the first thing you think of is Sion, but Sion is an Atlas alchemist, which is something totally different from those alchemists that devoted themselves to Western sorcery. It seems that the Atlas alchemists don't think much of Roa for that very reason, even though they both subscribe to the common idea that "everything flows". Also, contrary to what you may expect, Sion too is possessed of this same elitism, and looks down on Roa on principle.
…Huh? Then are Sion and Ciel actually on bad terms…?
|Shiki Tohno • Arcueid Brunestud • Ciel • Akiha Tohno • Hisui • Kohaku • Len • Michael Roa Valdamjong|
|Arihiko Inui • Aoko Aozaki • Barthomeloi Lorelei • Crimson Moon • Gransurg Blackmore • Kouma Kishima • Merem Solomon • Mr. Dawn • Narbareck • Nanako • Noel • Nrvnqsr Chaos • Satsuki Yumizuka • Shiki Nanaya • SHIKI Tohno|
|Akemi Yamase • Akira Seo • Brainwashing-Detective • Caubac Alcatraz • Curry de Marche • Forte • Fake Shiki • Hanei Misawa • Ichiko Inui • Keiko Arima • Kiri Nanaya • Magical Amber • Maiko Yamase • Makihisa Tohno • Master Panda • Mecha-Shiki • Neco-Arc Bubbles • Neco-Arc Destiny • Neco-Arc Evolution • Phantas-Moon • Sougen Jinan • Souka Tsukihime •|
|Melty Blood characters|
|Miyako Arima • Dust of Osiris • Mech-Hisui • Neco-Arc • Neco-Arc Chaos • Night of Wallachia • Riesbyfe Stridberg • Shiki Ryougi • Sion Eltnam Atlasia • White Len|
|Tsukihime • Tsukihime anime • Tsukihime PLUS-DISC • Kagetsu Tohya • Melty Blood • Melty Blood Re-ACT • Melty Blood Act Cadenza • Melty Blood Actress Again • Hana no Miyako|
|Advantage • Age of Gods • Ahnenerbe • Bajiquan • Church • Dead Apostle • Demons • Demon Hunter Organization • Familiar • Magecraft • Magical Girl • Marble Phantasm • Mystic Eyes of Death Perception • Reality Marble • Psychic • Tohno • True Ancestor • Vampire|