When you write it down, it looks terrible. But it works in practice, and that's all that really matters, isn't it?
Superpowers seem like an issue to me, especially if it's someone like superman, who's power originate from (and I'm probably getting this wrong, I don't read comics, so feel free to correct me) him being an alien and something about the sun being yellow, (wait, isn't the Green Laterns weakness the colour yellow? The sun's yellow, so how come he can go out in daylight?), or the x-men, who're mutants, it's an easy way to make a hero quick, but it makes heroic qualities seem like something that some people are just born with, rather than something everyone has, and they need to apply themselves to unlock.
Same goes for Villains too, if you're into that sort of thing. I mean, sure, the interstellar alien stargod who devours planets is a good villian, but he's not really bettering himself, is he? The Joker had to work to become the criminal mastermind he is. If he blows up the planet, that's an achievement.
