Illyana Rasputina is the sister of Colossus.
Illyana Rasputina grew up with her brother, Piotr, and their family on their farm in Russia. When Illyana was a little girl, she was almost run over by a tractor by Piotr jumped in front of it and discovered his mutant powers, saving his sister. Illyana grew up and was present when former Sovier troops destroyed their families farm. She escaped them and reunited with her brother, now the mutant 'Colossus', and his ally, the Jubilee. Illyana lead them to the enemies base but was kidnapped by Omega Red and almost killed before Wolverine saved her. After the former Soviets and Omega were defeated, Illyana and her brother reunited with their family and helped to rebuild their farm.
Alternate Reality Versions
Illyana was seen succumbing to the plague on her bed, with Piotr by her side, crying.