Imagine Breaker is one of the few things I'd put as capable of stopping One Punch Man. If you drop Touma into a world where everything is magic, parts he starts touching start going back to normal. And in a coherent way that doesn't chain react and wreck everything else. If the Sun goes around the Earth, it won't reverse itself unless he grabs the Sun. Which... he might be able to do, since the Sun is magic, and so holding his hand out is enough to make it not burn him alive as he approaches. Still need an air tank. Oh, and then after he touches it it's a NORMAL NONMAGICAL sun. So THEN he dies in a fire.