Illyasviel von Einzbern (AKA Illya) is the Master of Berserker in the Fifth Holy Grail War of Fate/stay Night. Though she initially appears as an adversary in the original visual novel, she becomes an ally to Shirou Emiya after a time, becoming something of a little sister to him. The daughter of Kiritsugu Emiya and Irisviel von Einzbern, she experienced much suffering and hardship throughout her life but maintains an upbeat personality while never forgetting how kind her parents truly were. An alternate magical girl version of her appears in Fate/kaleid, where she lives with her adoptive brother Shirou and is somewhat shyer than her main series counterpart.
In most of her dubbed appearances, Stephanie Sheh plays Illya. For the dub of the Fate/kaleid series done at Sentai Filmworks, Illya was dubbed by Cynthia Martinez.