Illyasviel von Einzbern , commonly known as , is a central character in the Fate franchise, first appearing in the visual novel Fate/stay night . She is the biological daughter of Kiritsugu Emiya and Irisviel von Einzbern, making her the older adoptive sister of the protagonist, Shirou Emiya . Although she appears to be a young girl of about ten years old, she is actually 18 years old during the Fifth Holy Grail War. Her stunted growth is a result of extensive homunculus modifications performed by the Einzbern family to make her the perfect vessel for the Holy Grail . Character Background & Personality
Her fate varies significantly depending on the timeline of Fate/stay night : Illyasviel von Einzbern
: As an Einzbern homunculus, Illya was born and bred to act as the Lesser Grail, meant to collect the souls of defeated Servants during the war. Illyasviel von Einzbern , commonly known as ,
: She serves as a vital ally and a major heroine. In the True Ending, she sacrifices herself to save Shirou and close the Grail, finally fulfilling her role as his "older sister." Alternate Universe: Prisma Illya Her stunted growth is a result of extensive
: She possesses a friendly and playful demeanor, often acting like a cheerful child. However, she also inherits her father's ruthlessness and can be cold-blooded and merciless when acting as a Master. Combat Abilities & Magecraft
: She plays a smaller role and meets a tragic end at the hands of Gilgamesh , who removes her heart to use as a core for the Grail.