The younger sister of Colossus, Illyana came to live with her brother after being kidnapped by Arcade. Soon after, the sorcerer Belasco captured her and held her in the pocket dimension Limbo. Belasco turned a portion of her soul demonic in nature. Belasco's spell gave Illyana considerable magical power, and she nearly killed him, but rather than give in to her demonic side she drove him from Limbo, becoming its new leader. She later joined the New Mutants as Magik.