History
Billy Taylor, along with his family, was kidnapped by Weapon-X and taken to the Neverland concentration camp. In Neverland, mutants deemed useful (like the Taylors) were branded with a green M on their hands, whilst those deemed less useful were branded with a red M and executed.
Billy’s mother helped him and his sister escape Neverland with the aid of a scientist called Dr. Windsor, only for it later to turn out that Dr. Windsor was Mr. Sinister in disguise who started experimenting on the children.
Powers
Billy’s eyes glow Purple when activating his mutant powers, but it’s not known what they actually do.