Adam Warlock
Superman is practically nigh invulnerable. It would take a great amount of force to hurt him let alone break his bones. I'm gonna list a bunch of people that I think can indeed snap his bones, and him possibly in half. They can use any kind of energy to amplify their strengths. But it has to be a power they already have.
EX: Odin can amp his strength with ambient magical and cosmic energy.
Magneto could also amp his strength in a similar way but using electromagnetic energy instead.
Supes does not fight back. He stands there as the beings listed below try yo break him.
Combatants attempting to do the impossible:
Thanos with let's say, a the same amount of prep he had hen he battled the champion.
Tyrant, Normal powered version.
Mr. Majestic
Supreme
Gladiator(Full Confidence)
Odin
Maelstrom - Superman gets to hit Maelstrom with 10 full power strikes before Maelstrom attempts to break him.
Darkseid
Doomsday
General Zod
Wonder Woman
Captain Marvel(Billy)
Classic Juggernaut
Savage Hulk - Strongest incarnation. If possible, at full strength. Is it even possible to gauge Hulk's full potential strength?
Cytorrak
Nabu
Champion Of The Universe W/Power Primordial
Mephisto Within His realm
EX: Odin can amp his strength with ambient magical and cosmic energy.
Magneto could also amp his strength in a similar way but using electromagnetic energy instead.
Supes does not fight back. He stands there as the beings listed below try yo break him.
Combatants attempting to do the impossible:
Thanos with let's say, a the same amount of prep he had hen he battled the champion.
Tyrant, Normal powered version.
Mr. Majestic
Supreme
Gladiator(Full Confidence)
Odin
Maelstrom - Superman gets to hit Maelstrom with 10 full power strikes before Maelstrom attempts to break him.
Darkseid
Doomsday
General Zod
Wonder Woman
Captain Marvel(Billy)
Classic Juggernaut
Savage Hulk - Strongest incarnation. If possible, at full strength. Is it even possible to gauge Hulk's full potential strength?
Cytorrak
Nabu
Champion Of The Universe W/Power Primordial
Mephisto Within His realm