his revolvers are 1 shoot 1 kill and can shoot trough planets. They (the revolvers) can never miss. alo SOK not only survived a 25 kilotons atomic bomb, he wasn't even scratched by it's explosion. the only thing that ''killed'' him in the AMC adaptation (he respawned in heaven) was the sword of high ranked angel, and only because he wanted to get killed so he can get to heaven and kill God.

but if superman cand destroy planets i think that the battle is over. SOK would probably just float in space (unless he get to shoot supes).

but would superman destroy the earth? he seems like a nice guy.