Anyone who has kryptonite and exposes him to it.
no a lightsaber would not kill superman
No.
superman killed badguys but not the inocent
kryptonite
no
Kryptonite
Metallo has tried in Superman/Batman: Public Enemies
In the 2013 film, Man of Steel Superman was forced to kill Zod.In the 1980 Superman II, after being stripped of his powers, Superman breaks his hand, throws him into a wall and he falls into a unknown mist. It is unknown if that actually killed him.
goku can kill superman becuse he can turn ssj4 and crush superman
The Beyonder
Yes he killed Superman.
Darkseid, his omega beams can kill superman if he's hit multiple times