How to beat Legion a Telepathic Mutant, well first of all i have a hard time beleving this character is the only one in any universe who got this kind of powers.
Powerful Sorcerers are more versetail than Legion as Doctor Strange, Doctor Fate or Loki and may come up with the same effects and a lot more. If this is enough to stop a God as Mighty Thor he would be gone a long time ago but he is several thousend years of age and have battled everything that may walk, crawl , fly or teleport. His greatest enemy beeing a Sorcerer of incredible power his half brother the God of mischief Loki. A Mutant born on earth may not compare to a half Elder/Asgardian God, his life force the God force is far beyond any Mutant or Human born.
Then give this Warrior God a weapon of Vast power the magical warhammer Mjolnir, its not a fair competition !