Villain
Mister Sinister
Marvel’s resident expert geneticist. Dr. Nathaniel Essex’s long history of experimenting on mutants is as horrifying as his origin and self-made mutations. In his quest for a perfect mutant race, Essex procures his subjects by any means, earning him a name as evil as his intent - Mister Sinister.Mister Sinister
X-Men (1963) #221
The First Full Appearance of Mr. Sinister! Naze and Storm continue looking for Forge at the Grand Canyon. Meanwhile, the X-Men have taken off to San Francisco to protect Madelyne Pryor from the Marauders. All goes well...until one mind-controlled magnetic Marauder shows up!X-Men: Colossus Bloodline (2005) #3
The villains pulling Colossus' strings reveal themselves, and fans will flip when they find familiar faces sneering from the shadows! Discover the extremely creepy secrets from Colossus' past. And you thought YOUR family had problems!X-Men (1963) #239
Jean Grey is alive! One of her teammates has known about this for quite some time, and Storm isn't too happy about it. Meanwhile, tensions near their breaking point between Psylocke and Rogue. Fists will fly!X-Factor (1986) #75
X-Factor's conflict with Ricochet is resolved after his true identity is revealed. The team takes on Mr. Sinister and his Nasty Boys, a gang of mutant followers. What is Sinister's next move? And will X-Factor uncover his motives before it's too late?X-Men (1963) #350
Gambit's greatest secret is revealed! And some sins can never be forgiven...Cable (1993) #6
The identity of the enigmatic Mr. Tolliver- revealed! A Sinister rendezvous leads to the return of a deadly foe! And Cable faces a twofold ambush- of his body AND mind!X-Men (2004) #203
As the Xavier Academy reels from Exodus's attack and the Marauders' true goals emerge, the X-Men finally find themselves in a position to take the offensive. But only if Iceman and Cannonball deliberately walk into an ambush from which they may not emerge alive. FEATURING ENDANGERED SPECIES Chapter 13 Beast's alliance with Dark Beast is put to the test as scientific inquiry turns into cold-blooded murder!X-Factor (2005) #27
MESSIAH COMPLEX PART 11 An X-Man's death reveals answers to some of the mysteries surrounding the new mutant, and creates a host of questions. The baby falls into the hands of a major player in the conflict, but things aren't always as they seem.