|Real Name||Nathaniel Essex|
|Alternate Identity||Mister Sinister|
|Powers and Abilities||Regeneration, Energy Blasts|
|Team Affiliations||Nasty Boys|
Savage Land Mutates
|Allies||Jack the Ripper|
Nathaniel Essex was a firm believer in Charles Darwin’s theory of natural selection. Believing that this could result in man becoming far greater than anyone could imagine, he began conducting tests on mutants, in hopes to evolve himself and to cure his wife, who had been taken ill to a mysterious illness for which no one could find a cure.
He concocted a serum that turned his skin chalk white and gave him almost instant regenerative abilities. The townspeople believed he had gone mad after learning of his experiments, and he fled across the world, fleeing from James Xavier.
With his newfound powers leaving him unable to age, he took an interest in finding those who could help him make the world a much more evolved place. He found Cyclops and Jean Grey, and thought their genetic material was perfect for his cause. After saving Morph and curing his body, he used him to try and spilt The X-Men up, and kidnapped Scott and Jean. The remaining X-Men eventually found him and stopped him.
After tricking Xavier and Magneto into meeting in The Savage Land, he robbed them of their powers and forced them to roam the dangerous, dinosaur filled land until they were finally kidnapped by the mutates. After luring them to The Savage Land, Magneto and The X-Men defeated Mr. Sinister, smashing him into pieces.
He would return to carry out his dream of a superior world, and fought the X-Men many times.
Mister Sinister was voiced by Christopher Britton. In the original airing of "The Final Decision", an uncredited actor played Sinister. However, this version was seen as too high-pitched, as it was only a temp-voice, so when Britton was cast he rerecorded the line.
The first version of the character outside the comics.
In the Comics
He was created by, and thus serves, Apocalypse.
- X-Men: The Animated Series - Which Scenes Never Aired in Reruns? at Comic Book Resources