We have /a/ related thread in /co/ all the time
Here's a criteria list for characters to meet in order to be able to beat Prime
-most powerful being in their Universe
-survived Universe destroying explosion from the epicenter
-have broken out of alternate dimensions unaided
Keep in mind the point of Superboy-Prime is that he is a ridiculously overpowered character. He's pretty much thrown a few tiers above everybody else. Not saying there's no /a/ characters that could beat him, it just really unlikely, since he was designed to be nearly unbeatable.