http://imgur.com/a/XBLfZ#0
I think it'd be perfect if he had the 'heart' of a mech (or even a daemon!) in his hand. After all, he's going around punching through tanks and meks, and in a few games he's caused them to explode on the spot (and live!!).
How could I go about doing this? I can't find any suitable bitz, I'm just after a simple power-core/large heart main part with cables/tendrils hanging off it, like he's literally just ripped it out with his power first. Bonus points if it's a heart, then I can coat his fist with my new blood effect paint with a legitimate reason!