Mister Clean

Mister Clean was an ultra-violent opponent of the popular Marvel comics superhero team, the X-Men, being a sadistic anti-mutant terrorist he would become one of the X-Men's more recent and deadly opponents - aiding the Church of Humanity in enacting a massacre upon several mutants : he code-named himself "Mister Clean" as a mark of his twisted occupation as a "genetic cleaner" (basically a genocidal shock-trooper).

Personality
a sadistic, merciless murderer by heart Mister Clean saw himself as a man destined to cleanse the world of what he viewed as "mutant filth" - in his eyes any deviation from the "norm" was to be put to death by his hands : in a common hypocresy amongst anti-mutant humans he was willing to undergo experiments to gain superhuman abilities despite hating superhuman beings simply for existing.

Powers / Abilities
Mister Clean was a merciless killer armed with a flamethrower by which to murder his victims, he also had his skin chemically-altered by the Church of Humanity - allowing him to be virtually impervious to all harm, even Adamantium (though he was not immune to burns, as this was Wolverine's ultimate means to end the terrorist's life and stop his rampage).

Trivia

 * Mister Clean and his massacre is a parallel to the infamous Morlock Massacre performed by Mister Sinister and his gang years previously, unlike the Morlock Massacre the recent massacre was a human-on-mutant hate crime (while the Morlock Massacre was ultimately a mutant-on-mutant hate crime).