Illumi is the eldest son of Silva and Kikyo and was raised from birth in the art of assassination. He trained Killua to become an assassin. Illumi was sent by his mother to watch over Killua, who also entered the Hunter Exam. He has a twin sister named Kurayami who never leaves her bedroom and always wears a mask. She has white hair and blue eyes. Her nickanme by their mother is "Cheshire"