as a guy who used to read a lot of comics i can remember not just one, but three people kicking the shit out of superman :
Lobo : happened just before death of superman thing. lobo beat the shit out of superman, and threw him into the sun.
Batman : In the Dark Knight Returns set in the future, an old batman teamed up with green arrow and they shot a kryptonite arrow into him, killing him.
Doomsday : Yeh Superman came back after a while, but doomsday literally killed superman of the present day, no problem had.








