Subject's names: Nathaniel Richards, Pharoah Rama-Tut, Iron Lad, Victor Timely

Subject's powers: Time travel/manipulation

Why this power seems good: Hey, it would be super-neat to be able to just jump back in time with a lighter and suddenly be King Shit in ancient Egypt because you can make magic-fire from a metal rock. Or to jump into the future and re-shape it in your image (i.e. remaking all the buildings into Krispy Kreme stores).

Why it might actually suck: Go enough places and do enough shit and you're bound to encounter the one motherfucker that you really don't want to deal with: Yourself. This has happened to Kang and his older self, Immortus, many times. Sure, the Avengers will try to harsh your buzz, too, but the real problems will come from the older and/or younger you, who, as I'm sure you're well aware, is a dick.