Julian has a serious air about him, but he once looked much less angry in pictures owned by Beatrice. Miyu calls him a "counterfeit who is clinging to a ghost", who used his father's death to disguise himself. He is angered in being called a fake, claiming that he is Darius. He currently claims to wish to save the world and fulfill the Ainsworth's dearest wish along with Erika. This involves the fulfillment of his own legend, and it requires the sacrifice of Miyu as the Holy Grail. Shirou calls him a "Champion of Justice" wishing to sacrifice one person for the greater good, while those opposing his ideals are technically setting out to save one person for the world. Shirou claims that he will accept the evil that comes with stopping him, while Illya plans to somehow save both Miyu and the world.
Julian claims that the conclusion of his legend is already set in stone. Although he does not care about ordeals he considers inconsequential to his overall plan, he will seek to destroy all who would interfere with his legend and his sought-after ending. Perceiving the events of world as a sort of performance to his legend and obsessed with dramatic staging, the people around him are considered "players" whose actions have already been determined. Considering some of them like Illya and Tanaka to be critical, he does not wish for them to die too early in the stages of his plan. He greatly hates Shirou for interfering in his plans, claiming that he has no role in his legend.
He acts very differently under the guise of his father, and it is unknown how much is influenced by him or his father. Still focused on bringing about his legend, he displays a bipolar personality switching between calm, sometimes comedic conversation and manic declarations. He acts out the role of his father, considering Erika to be his daughter, watching over her and telling her not to leave the estate without permission, and making no mention of himself. He dotes on her for the most part, and her obliviousness to his actions causes her to see him as completely normal. He only becomes angry with her should her actions somehow go against his pursuit of his legend. Beatrice and Erika do not refer to him as Julian unless he is outside of the guise, and he tells Erika that he is her father, brother, and the only person on her side.
Due to the impending death of the World, Julian searched out Mystic Codes, magical implements, and vessels from around the world to replace Noble Phantasms and the Holy Grail. Unsuccessful over countless attempts and left with a pile of failures, Miyu Edelfelt was made as the successful Holy Grail capable of saving the world and captured. Starting the Sixth Holy Grail War with the creation of the Class Cards, he began an unknown process to bring about the ascension of humanity into beings able to survive in the new world by sacrificing Miyu. Darius Ainsworth died at some point in time, and his exact level of involvement in the process is unknown. Julian assumed his identity by cloaking himself in a conceptual duplicate of his father. Miyu's brother, Shirou, fought them in order to free her, allowing her to escape to the other world, and he was captured to use as leverage against her. With her escape, the process was put on hold until Gilgamesh's Enuma Elish opened a path between the worlds that allowed Angelica and Beatrice Flowerchild to recapture her.
Fate/Kaleid Liner Prisma IllyaEditJulian, under the guise of Darius, first appears as Illyasviel von Einzbern, Gilgamesh, and Tanaka's attempt to rescue Miyu ends in battle with Angelica and Beatrice. Before Beatrice can use the full power of Mjolnir, he orders her to stop through projecting his voice to them, and politely introduces himself as the head of the family. Apologizing for his servants, he says that their return should not be impeded. He later shows up at their temporary base, a school, after Erika travels there to meet Illya. Seemingly inconspicuous, he thanks Illya for watching over his daughter and suffers from the cold. As the failing wards on the school are replaced to identify him as a threat and Illya recognizes his voice, he becomes more serious, declaring the alarm to "lack style" for the "opening act."
As Bazett Fraga McRemitz charges out to meet him, he claims that her ascetics with the barrier lack style, complaining that it needs to be made to "suit the scene" and displaying Apneic Beauty as an example of a true barrier. Declaring that he wishes to have a calm discussion with Illya, he introduces himself, explaining his role and calling himself the "demon king" that Illya must kill. As Kuro and Bazett try to destroy it from the outside, he goes into a manic display at the idea of Miyu escaping into an alternate world, making her first friend through her their ordeals, and then ending back in his clutches, calling it a "mythology that crosses world lines." As he continues, thanking Illya for retrieving his cards and saying there is no need to return them, Erika stops him before he reveals more to them.
The oxygen within the barrier begins to run out, so he plans on releasing it until Tanaka blows a hole through it. Annoyed that an "extra" has plagued his stage, he moves to remove her right away. The other three move to repel him, but he easily blocks their blows and subdues all four of them with Authoritarian Personalism. As he moves to finish off the "extra with no lines", Tanaka mentions the word "Counterfeiter", surprising him and causing him to declare that she has a role after all. Although it would be easy for him to finish them in that state, he does not wish to end it without creativity like that. He welcomes them to his stage and tells them to do as they please, declaring the resumption of the Sixth Holy Grail War before leaving with Erika.
He visits Miyu that night, linking to her window from another room with Flash Air. He tells her that it is time for her "work", using her blood to continue writing his legend. She shows resistance for the first time, but she is quickly placated after he threatens to hurt her brother to punish her. Telling her that she should be used to the process already, she goes through great pain at the expense of carving another of his tablets, noting to despair it describes the events since her return. He sleeps throughout the events of the next day, with Erika having Angelica kidnap Illya in order to appease Miyu in a warped manner. He awakens after Illya manages to escape and battles Angelica with Kuro, meeting with the sulking Erika and Miyu as they talk about the situation.
After Erika explains the situation to him, he is greatly angered at her possibly ruining his story, spanking her with great rage until Miyu interrupts him. He instantly loses his anger, instead complaining about Angelica ruining the garden and contemplating what he would do if Illya were to die too early. Miyu becomes upset at the idea of Illya perishing, threatening to commit suicide should anything happen to her. Julian declares that he won't let her kill herself, projecting a mental image of her to the battlefield so she can see the events happening. Seeking to cause her to despair by showing their desperate battle all for the sake of saving her, Illya's impassioned speech about saving both Miyu and the world causes him to burst into laughter. He claims that it is necessary for he to be motivated enough to rescue Miyu, claiming that the hope she presents for Miyu is the "deadliest of poisons."
With the arrival of Bazett and Gilgamesh to stall Angelica, Kuro uses the opportunity to destroy the tower of the castle holding Julian, Miyu, and Erika. He is annoyed at the nuisances who don't know the proper "time and place for things", and he is met by Illya installing the Saber Card. He easily blocks her strike with a single hand, but she reveals her true purpose was using the included Caster Card's Rule Breaker on him through Kuro's suggestion. Though Kuro believes it should be enough to destroy the entire ritual, it instead only dispels his father's duplicate. As he suffers and falls out of the duplicate, the Flash Air keeping the estate displaced with the mountain and invisibility Bounded Field around the estate are dispelled.
Julian is greatly angered by the events, and he is brought to safety by the returning Beatrice, who almost slips up by calling him by his real name. As Miyu is reunited with Illya, he is perturbed by the fact that she is looking down upon him from above. The fact the the "vessel" is attempting to escape with hopes of the future and that her brother, being saved by Gilgamesh, is not able to be used as leverage causes him to begin to laugh hysterically. He abruptly returns to normal, claiming that it is impossible to laugh at such an unamusing situation. Claiming that all they have done, their own feelings, and their own wills are all nothing more than inevitable "ingredients" for his story, he brings for the large cube object above the restored mountain.
He claims that his legend will never crumble, and that they cannot resist because the conclusion to his legend has already been determined. Miyu reveals to the others that "Darius" is really Julian, and angered by the claim of him being "fake", he snatches away and destroys the Caster Card. He tells Illya that he will forgive her for all of her minor transgressions against him, but that he will crush anyone trying to interfere with his legend. Kuro ineffectually tries to damage the cube without any result, and Erika proceeds to ask him what Miyu means when she claims that Erika isn't her friend. He quiets Beatrice after she beings to rant about how the world hates them, squeezing her heart and making her slump down in delight.
He tells Erika that she can trust none other than himself, claiming that they will fulfill their family's wish and save the world. She tells him that she believes in him as she allows herself to be drenched in the mud from the cube, bringing forth a number of corrupted Heroic Spirits. Julian exclaims that Miyu may run if she wishes, but that there will be no escape from their darkness. As her friends are hard-pressed to fight the heroes, he tells Miyu that they seek the Holy Grail and that they will not stop filling the world with despair until it is obtained, enticing her back to him with the promise of stopping such a disaster. Before she responds to him in despair, Illya stops her by telling her nothing good will come of it, and Shirou, broken out of the prison, arrives and concurs with the statement.
As Shirou exclaims that he will fight him, he angrily shouts out Shirou's name as Shirou proceeds through the battlefield towards his location. Projecting Ig-Alima to act as a ramp to lead to his elevated position, Shirou runs towards him, causing him to angrily say that Shirou has no place in his legend.
Julian is very powerful, notably in his use of Flash Air to displace an entire mountain with his castle. He is able to connect windows and doors throughout the castle to one another, regardless of their actual geographical location. Much like Angelica's use of shifting space, he can grab at a person's heart by displacing their body around his hand, create a portal by displacing space to reach out to someone, and he move his entire body through them. He can render his entire estate invisible to those outside through a Bounded Field around it, and he manages to hide the large cube object above the castle in a similar manner. He can remotely project his voice to others without sound being produced, view events from far away, and he can project the consciousness of others.
He has a conceptual duplicate of his father that is clad around him normally, made up of a mist-like substance. He is powerful in this state, showing the ability to deflect attacks from Bazett and Kuro easily, catch Excalibur bare handed, and easily dispatch four strong opponents with one Class Card. He uses the unique Noble Phantasms Authoritarian Personalism, Apneic Beauty, and an unnamed dagger from three unknown Class Cards. After being dispelled by Rule Breaker, he shows the ability to briefly clad himself in it again and dispel it afterward.
He has power as the Holy Grail War's Rule Master, the only person with the authority to create and destroy Class Cards. Simply crushing one in his hand is enough to completely destroy it.
Julian is in possession of a large cube object with magic circle-like patterns situated over the estate behind a Bounded Field to conceal it. It is durable enough not to be harmed by Kuro's Noble Phantasm arrows, and it is called a powerful object "not meant for human hands." It has some relation to Miyu as the Holy Grail, saving the world, bringing about his legend, and Tanaka's mission to destroy the Ainsworths. It contains a mud like that of the corrupted Class Card Heroic Spirits, and after pouring over Erika for an unknown reason, it is able to spread out. Julian calls it the "Ainsworth's darkness" that will spread out enough to turn the world into a prison.
The mud is capable of manifesting countless corrupted Heroic Spirits, all those who sought the Holy Grail and failed. They are beasts driven only by their desires to obtain the Holy Grail, and they will continuously emerge until they find it and fill the world with despair. They have both individual strength and numbers, overwhelming all of Illya's group without them being able to even damage them. Unable to even buy time against the horde, only Shirou displays any ability to damage them. They can attack in a great rush, and display some coordination in the launching of a volley of arrows.
Julian has been weaving his own story in an attempt to make it into a legend for an unknown reason. It has something to do with saving the world and humanity from its current state and ascending humanity to a new level able to survive in the coming new world using Miyu as the Holy Grail and the mysterious object for some purpose. He has created Class Cards containing Noble Phantasms unknown to Gilgamesh even though his treasury contains all of them. If they exist, especially powerful ones like Julian displays, he should know of them. He has the "story" all planned out, even involving current events, and those who change even the slightest details earn his ire. Factors like Illya dying too early before the final battle, noted to be a long ways off, could change it too much.
He is actively carving his legend into tablets that have something to do with actualizing it. Each is filled out by taking Miyu, laying her on a slab, and generating a large, thorned plant that stabs through her hands to drain blood into a magic circle that subsequently fills out one of the carvings. The ritual does no damage to her body, only draining blood and filling her with phantom pain. He has filled five of seven slabs, with the latest telling of events that have transpired since Miyu's return to the their world. Even without her, another passage will be added upon the cube leaking out its mud. His story should attain the status as a legend once all seven are filled, and he equates its ruination to the death of humanity. Tanaka is notably not in the records, and he considers her an "extra" in the story until she mentions the word "Counterfeiter."