20 Most Powerful X-Men Villains Of All Time
19. Sauron
Named after the unseen Lord Of The Rings antagonist, but not quite as powerful as that all-seeing eye, Sauron in the X-Men comics is a scientist with the mutant gene who is a sort of psychic vampire. He has to feed on the lifeforce of other people (fellow mutants are especially tasty), and when he does he turns into a dinosaur man.
Unsurprisingly, when he's half-man, half-pterodactyl Sauron spends a lot of time in the Savage Land, that mysterious island on Marvel's planet Earth where Stone Age life remains (including cave men and sabre-tooth tigers). Which is a veritable feast for him, because superheroes always crash land there.
The trick with Sauron is that, not only is he more powerful in his dinosaur form, but when he absorbs the lifeforce of mutants or other metahumans he gets infinitely more powerful than just regular people/mammoths, meaning in theory he could absorb all the X-Men's powers and be pretty much unstoppable.