[quote=@Oliver]
<Snipped quote by Dannyrulx>

Sounds like a plan. It's been edited to accommodate the 3 points.
I didn't plan on it being an energy drain per se. Kind of more like being in an airlocked room. As in, he'd be fine for a few hours, but eventually the lack of fresh air would make him dizzy. But if you'd rather have that be the main downside to the quirk, that's fine.
[/quote]

I think the main issue with practically every non-mutant perk is that it actively requires the user to do something, which takes energy and focus. Mutants have focus down pat naturally, but the energy cost is always built in, so there's that I suppose.