12 Most Dangerous X-Men
7. Magik
...That title goes to Magik, a.k.a. Illyana Rasputina, a.k.a. Colossus's kid sister.
As her codename would suggest, Magik is not only a mutant, she also has a pretty good grasp on actual magic. And when we say "a pretty good grasp", we mean she actually held the title of Sorcerer Supreme after learning the arts of necromancy, possession, astral projection, magical creation, metamorphosis, psionic shielding, force fields, demon soul acquiring, and both black and white magic during a stint in the Limbo dimension.
That sounds like a lot on its own, but let's not forget she also has her natural mutant ability of teleportation, which allows her to travel not just huge distances, but also between dimensions and through time itself. So, all in all, she's got a lot going for her.
Oh, and she also owns Eldricth Armour and the Soulsword, which make her invulnerable to any and all magic used against her. So don't even bother trying.
As you can see, Magik is pretty well set up in terms of dangerously excessive power. So, what do you get for the girl who has everything? Why, the Phoenix Force, of course! As if she wasn't dangerous enough on her own, she has also been imbued with the cosmic power that gave Jean Grey the ability to kill billions in an instant. She's really starting to make her brother, a big man made of metal, seem a bit silly in comparison.