This question is narrowing the choices down to ONLY mutants. Characters like Thor, do not qualify. And yes btw, this list is based off characters at their full potential.
1) Jean Grey 2) Jim Jaspers 3) Franklin Richards 4) Professor X 5) Scarlet Witch 6) Quentin Quire 7) Ice Man 8) New Sun 9) Elixir 10) Cable
Feel free to post your top 10 below!
Btw, my other candidates were:
SENTRY: -I didn't put him in because his full powers were never really explained to a degree that would definitively put him above any of the people in my initial top 10. But harvesting the power of multiple suns... is pretty damn powerful indeed.
APOCALYPSE: Arguably the first mutant ever and an immortal, seems like a sure lock for top 10 contender ship, but though powerful, his full range of powers has never really been developed or even brought up theoretically. Plus it seems he uses more technological advancements as of late, rather than his natural mutant abilities. One can use this argument for Cable... but exactly how many times has Cable beaten Apocalypse. Exactly.
JAMIE BRADDOCK: Here's an Omega level mutant that I left out of the list. Couple of reasons, while his abilities (which btw is an almost guarantee shoe in for omega status) is undeniably powerful, they are arguably watered down and lesser evolved versions of Jaspers & Richards abilities. And while Jamie has gotten stronger, and his potential has risen to an almost cosmic level... it's just impossible to take a man in a thong seriously.
HULK: I know some uber elitist douche is reading this going, HULK? Psssh! (insert meaningless rant here) But screw them, this is my list lol. I pick Hulk because he is basically unbreakable and his powers in terms of strength are absolutely limitless. He has lifted mountains. Survived Johnny Storm's strongest Nova Blast. Hell he conquered an entire planet and "ate" Galactus. Come the end of civilization in the Marvel universe, only a few things will survive... one of them is the Hulk. Ps, did I mention that he once threw Super Man in outer space? He gets extra points for that.
Lastly, I was going to mention Thanos... but he was beat by Squirrel girl. I'll leave it at that.
"Not in the Marvel continuity. They need that X-gene thing."
This is true for mutants who were born as mutants. But for people who attain their powers unnaturally after birth, via experimentation or accident... much like Hulk or even Mr. Fantastic, I don't think they would need it to classify themselves as a mutant. Seeing as they both mutate into a form that is impossible for a normal human to reach.
And hey, I do believe that Franklin Richards is considered a mutant, with mutant powers... despite being the birth child of Mr. Fantastic & Invisible Woman, both of which, were not born with the X gene.
Given all of his combined powers, yes he is extremely powerful. But he also doesn't have full control over all his abilities, and sometimes, even of his own body. Given all the personalities he's absorbed, and several of them taking over his thoughts and actions, at sometimes random occurrences... he's just too unstable a character to be in the top 10 for most powerful mutants in Marvel history.
He is an omega level mutant though. And if he had 100% control of all his abilities, and above all, himself... he'd easily be top 5... maybe even top 3.