Much like the other Einzbern homunculi, Illyasviel has crimson eyes and long white hair.
Similar to her mother, Irisviel, Illya also bears a genetic resemblance to her ancestor, Justeaze Lizrich von Einzbern, who was responsible for the formation of the core of the Holy Grail.
She has a minor role in Fate/Zero, she first appeared in the beginning when she was born.
As she grows up, she was very fond of her father which surprises Saber as Saber thought Kiritsugu was a cold person.
, often referred to as Illya, is the Master of Berserker in the Fifth Holy Grail War of Fate/stay night.
She is the daughter of Kiritsugu Emiya and Irisviel von Einzbern, both whom participated in the Fourth Holy Grail War, and the adoptive older sister of Shirou Emiya.
In the Fate/Zero Drama CD, she was born out of love between Kiritsugu and Irisviel.
She will be Kiritsugu's reason for living when he comes back from the war.Kiritsugu while carrying her realizes that she stopped growing.Before he leaves for the war, Kiritsugu promises to return to Illya, who promises to wait until he returns.With her father abandoning her after the Fourth Holy Grail War, she became angry with Kiritsugu, and consequently, Shirou.Angra Mainyu appeared to her in form of her mother and was turning Illyasviel against her father & adoptive brother.The Einzbern, one of three families of sorcerers involved in the Holy Grail War (the others being the Tohsaka and the Makiri/Matou), were responsible for creation of the vessel which the souls of the defeated Servants would go into, while the Makiri created the system of Masters and Servants and the Tohsaka supplied the land which became Fuyuki City.