Mr. Sinister is a fictional supervillain appearing in comic books published by Marvel Comics. Created by writer Chris Claremont and artist Marc Silvestri, he first appeared in The Uncanny X-Men #221 in 1987. Known for his pale skin, red eyes, and distinctive black and white costume, Mr. Sinister is a geneticist with a deep obsession for mutant DNA, often manipulating it for his own purposes. As a formidable foe of the X-Men, Mr. Sinister possesses various powers, including superhuman strength, agility, and the ability to manipulate his own genetic structure. He is often associated with the Marauders, a group of mutant assassins, and has a complex history involving characters like Cyclops and Jean Grey. His ultimate goal is to create the perfect mutant, often leading to conflict with the X-Men.