He was an overcapped, overachieving Stingmon to begin with, which is a decently strong species, and then he got peak level evolution modifiers on top of that.
When fully developed, he'll probably be a peer to 'ordinary Megas' (Ones that aren't part of the Big Groups for instance), right now, he should be a match even for mature Ultimates who aren't particularly talented. Okuwamon is only an 'ordinary' Ultimate, in the sense that any 'mon who can get to the Ultimate stage in the first place is 'Ordinary' anyway, and given the fact our bois are managing to leave dents in him even as Champions--pretty sure that our team with Beat as the front-runner is going to dumpster this guy now.