A German aristocrat who came to Japan to participate in the Fifth Holy Grail War. She is the Master of Berserker and has excellent control of him.
Illyasviel is the biological daughter of Irisviel and Kiritsugu and the adoptive sister of Shiro. While seemingly appearing as a young girl, Ilya is actually one of the Einzbern family's homunculi, an artificial human created by applying sorcery to sperm cells. Unlike other homunculi created by the Eisenberns though, Ilya was born through natural means via Irisviel. The family's intent with Ilya is to use her as a vessel for the Holy Grail in the event there was another Grail War. As a result, they made heavy modifications to her body to maximize the potential of her magical circuits, which effectively slows Ilya's growth rate as a result.
Ilya stands at 52 inches tall (133 centimeters) and physically appears as a young girl. Despite being slightly older than Shiro, she has a distorted growth rate as a result of her origins. She has waist-long silver hair and red eyes. Ilya normally wears a collared purple shirt with long sleeves and a purple scarf, a long white skirt and purple boots.
Ilya's role in Fate/ Zero is minor as Irisviel and Kiritsugu tended to her before they left for participation in the 4th Holy Grail War and served as the latter's motivation for participating in it. She was very fond of her father, which surprised Saber who believed her Master had a cold personality.
Because Kiritsugu had destroyed the Holy Grail, the Einzbern family seen this as an act of betrayal and would forbid him from returning to see Ilya by refusing to allow him through the family estate's barrier. The Einzberns would manipulate Ilya into thinking that Kiritsugu had abandoned her and took advantage of this hatred to strictly train her into being a Master who would bring the Grail to the Einzbern family.
Ilya would become the Master of Berserker for the 5th Holy Grail War, who was summoned through using a slab of rock from a temple being used as a catalyst. His summon came two months before the start of the Grail War because of the Einzbern family cheating to cast the summon early by gathering material coming from the Holy Grail. In his first act, Berserker would save Ilya's life by slaying a pack of wolves attacking her when left to fend for herself in the wilderness as part of her training.
While participating in the Grail War, Ilya would live in the Einzbern Castle outside of Fuyuki City, having Berserker and two of her maids, Leysritt and Sella, accompany her.
Ilya and Berserker would become the second major threat that Shiro and Saber have to confront in the Fate Route following Rider's defeat. Knowing of Shiro being her foster brother, Ilya sought him out as revenge on Kiritsugu for his perceived abandonment of her.
She would abduct Shiro shortly after Saber became weakened after Rider's defeat and tries talking him into becoming her servant. When he refuses, she threatens to send Berserker to attack Rin and Saber before the two and Archer arrived to rescue him. Archer sacrifices him to buy time for the three to escape from the castle and manages to take five of Berserker's lives before his death. Ilya and Berserker search the nearby forest for Shiro and the girls where during their search, Saber's strength gets replenished as a result of Rin's ritual linking Saber to Shiro's magic circuits.
The next day, Berserker engages in battle with the three where Shiro and Saber manage to defeat him when Shiro traces Saber's original sword, Caliburn. With Berserker defeated, Ilya joins the Emiya household where she becomes increasingly attached to Shiro and finding Taiga to be a nuisance.
Ilya's role is lessened in this route as she would be killed by Gilgamesh early in the route when he rips her heart out after defeating Berserker.
Unlike Fate route, Ilya starts off a friendly relationship with Shiro in this route at the same park they met before when she abducted him in Fate. Here, Ilya tells Shiro about her past and her family's artifact, the Dress of Heaven.
She allies with Shiro later on when her castle is attacked by Zouken and Berserker becomes corrupted by Dark Sakura into the blind and decrepit Dark Berserker. After killing Dark Berserker, Shiro takes Ilya to meet with Rin, where Ilya reveals everything concerning the Holy Grail and Angra Mainyu's revival. The three work together at creating the Jeweled Sword of Zelretch, which Rin decides to wield against Sakura. Rin and Shiro leave Ilya behind as they go off to stop Angra Mainyu's revival.
Realizing that Shiro would still die, even if he managed to reach the Grail, Ilya would locate the Dress of Heaven to use in protecting Shiro. As Shiro is about to sacrifice his life to destroy the Grail, Ilya uses the Dress of Heaven's power to protect his soul from death at the cost of her own life. Shiro's soul would later be transferred into a body created by Touko Aozaki, though through various trial and error methods over a period of six months because of Ilya's magic being imperfect.
On the surface, Ilya appears to be a cheerful and outgoing girl who is easy to talk with and can be fairly mischievous. However on the inside, she suffers from loneliness and anger towards her father Kiritsugu for believing that he abandoned her. She also usually displays a cruel, merciless streak as Kiritsugu, demonstrated when she ordered Berserker to kill Shinji Matou after Rider's defeat in the Fate route. Ilya's feelings for Shiro are conflicted where while she cares for him like an older brother, she is jealous of the fact that he was cared for by Kiritsugu and believed that she was abandoned by her father for Shiro.
Because of being raised to be a vessel for the Holy Grail, Ilya possesses an unlimited supply of mana and a large number of magic circuits. As a result, she is able to easily control and supply mana to Berserker. She is capable of using the Mystic Eyes of Binding, a spell cast through one's eyes that allow one to cripple their target via eye contact.
As a result of being a homunculus, Ilya is capable of wearing her family's Mystic Code, the Dress of Heaven. The dress grants one the ability to materialize souls and transfer them to other bodies, being an imperfect form of Heaven's Feel, one of five "true magics" that grants one the power to manipulate and control souls. The dress can also be worn by elementals and dwarves, but humans will be turned into gold upon contact with it.
Fate/Stay Night: Unlimited Blade Works
An alternate retelling of Fate/Stay Night based off of the original visual novel's scenario by the same name. It primarily focuses on Shirou, Archer, and ...