Ozymendias may not have a lot of feats, but the ones he has are pretty awesome. With that much prep and better rescources than Prometheus I think he would build something as he did in the Watchmen comic and vaporize him.
However, if Prometheus can get intel on Ozymendias then he may have the better advantage. If it turns into a martial arts combat then I think Ozymendias takes it.
Sometimes I think that Ozymendias was some sort of Batman/Captian America Clone.