10 X-Men Villains With The Biggest Body Counts

Before he was Mister Sinister, Nathaniel Essex was a visionary geneticist during the Victorian era. When Apocalypse transformed him into a mutant, Essex's obsession with evolution amplified and he promised to dedicate his life to creating the perfect lifeform.

For over a century, Sinister forced hundreds of people to serve as unwilling participants in his experiments. One time, he infiltrated Weapon X's Neverland concentration camp and broke the prisoners out, claiming he would take them to safety. In reality, he transported them to his personal lab and experimented on them, resulting in many fatalities.

However, most of Sinister's kills are not by his own hands but by his minions. Believing the disfigured subterranean mutants, the Morlocks, were scientifically unnecessary, Sinister worried their existence could harm the genepool, and thus, ordered for their extermination. Even though the X-Men, X-Factor, and Thor did what they could to protect The Morlocks, Sinister's underlings slaughtered hundreds of the sewer-dwelling outcasts. Although Mister Sinister claims his actions are in the best interests of society, this single act guaranteed him being labelled as a genocidal maniac.