The only Kryptonian who could possibly be more powerful than a Kryptonian god would have to be one capable of transcending the very pages within which all beings in the DC Comics universe — mortal or otherwise — are bound. There is, of course, only one being of this kind: Superboy-Prime, the Clark Kent of Earth-Prime.
Earth-Prime is, for all intents and purposes, the “real” world. For example, on this Earth, DC Comics is a comic book company that publishes stories about Batman, Superman, Green Lantern, etc., with the writers of these stories being able to derive inspiration from a subconscious awareness of the multiverse (similar to a concept referenced in an episode of the “Justice League” animated series). The Kal-El of this reality is also sent to Earth, raised by a family of Kents, and given the name Clark, and eventually becomes the superhero “Superboy.” Tragically, Earth-Prime was destroyed by the Anti-Monitor, which ultimately drove Superboy insane to the point of trying to conquer the New Earth (the mainstream Post-Crisis Earth).
Superboy-Prime is as strong as any version of Superman throughout history, but without the heavy canonical asterisk. When he took his first villainous turn, he was able to punch reality so hard it shattered — and in his most recent appearance in the “Dark Knights: Death Metal” event, his battle with the nigh-omnipotent Batman Who Laughs sent literal, destructive shockwaves throughout the multiverse. Most notably, for our purposes, is that he’s proven his might against several other Kryptonians, nearly killing Power Girl with one punch, surviving an explosion that killed the “false” Superboy, Conner Kent, and beat that same Golden Age Superman to death with his bare hands. (Did we mention he also lacks the usual Kryptonian weaknesses to magic and Kryptonite?)
In raw power alone, Superboy-Prime is the strongest Kryptonian DC Comics has ever created — and they should know, because he once showed up to their offices in person to attack them for writing about him too much.
Wait, is it too late to pull the plug on this? Anyone? Hello? I think I see red eyes glowing outside my window…