Mister Sinister is a supervillain appearing in American comic books published by Marvel Comics. Created by writer Chris Claremont, the character was first mentioned as the employer behind the team of assassins known as the Marauders in The Uncanny X-Men #212, and later seen in silhouette in The Uncanny X-Men #213, with both issues serving as chapters of the 1986 "Mutant Massacre" crossover.
