uhhh neither? I was born with my powers, they don't come from anywhere but me.

long story short, the X-Men are mutants, which is a term that means we're all born with our powers. a lot of regular humans don't like the idea of mutants just, you know, existing alongside them. so the cause of the X-Men is to try to get humans to like us better by beating up the mutants that use their powers for crime or to terrorize people.