[@King Tai] The edit in his history is good. As for the ability, just remember that this is just weight manipulation, nothing else. This can get really tricky. 

I think a ton is too heavy. Given his frame and built, I'm assuming he'd be around 50 something kilograms at most. Thrice his normal weight seems pretty heavy to me; he'll just train to increase his limit. I don't mind him being able to change his weight to 0 kg, but just be aware that going to the extremes of weight may have repercussions. Is this the final description you'll be giving your ability? I'll be basing my posts involving your character on how you describe his ability and what he can do with it.