Spawn's not overrated. This guy makes a match for the most powerful of either universe. It would take someone like Rune King Thor or something like that to take him on an even level. The only person that I know that could defeat him is Dr. Strange.
Also, I'm saying 2nd age would win (king of hell). I don't know about 3rd age though. He's not as powerful as the 2nd. He'd be more of a match than anyone else we've brought up to this point, but it wouldn't be easy.