Steelheart's invincibility is not just skin deep it is stated that he can't die of suffocation and his blast where casually disintegrating buildings really he would probably beat the Prof and Obliteration in a battle of attrition he would just outlast them. And he can pretty casually fly through steel structures easily and he is physically one of if not the strongest Epics. Prof would last a while but his weakness would probably be triggered while fighting Steelheart and he would lose. Obliteration would simply lose in a battle of attrition eventually he would get disintegrated from a blast. Steel heart no sold a death beam that insta killed every thing it hit and he was immune to all human damage.
