20 Most Powerful X-Men Villains Of All Time
9. Juggernaut
Cain Marko isn't technically related to Charles Xavier, and he's technically not a mutant either. The step-brother of Professor X made his life hell when they were kids, and that only got worse when he discovered the Crimson Gem of Cyttorak in a cave somewhere and it imbued him with the indestructible power of the Juggernaut!
Coupled with that big helmet he wears over his significant dome, nobody can stop the Juggernaut! Psychic blasts are kept out with that much like Magneto's own special hat, and he's very much invincible in every physical sense, which makes him a tricky customer indeed. He only managed to be a good guy very briefly, too.
Along with the indestructible thing he's also super strong and powerful, meaning he can destroy...mostly anything he puts his hands to. Thankfully, he doesn't have any further powers to wreck the X-Men. Unfortunately, he often doesn't need to, since beating them up with his bear hands does the trick just fine.