First, a little about our challenger:
Superman is the last surviving son of the planet Krypton who gains incredible super powers upon arrival on our planet. He has amazingly enhanced abilities such as strength, speed, invulnerability, and flight. He is also gifted with with laser and x-ray vision as well as super icy breath. If there was a technical definition of 'overpowered' it would be Superman. He is the idol of every man, women and child in the DC universe (who isnt evil).
Scenario:
The powers that be in the cosmos have grown eternally bored with watching the exploits of the 'super beings' of the multiple universes. A debate has been raging in the minds of the endless ones as to who the most powerful warrior in the endless realities. Two champions have always topped their list, Superman of Krypton and Thor Odinson of Asgard.
These two warriors are the most true of heart in their realities and have been chosen to do battle in order to save their reality. In the vein of the immortals sense of humour, these two 'boy scouts' will be forced to do battle to the death or face their entire reality being destroyed.
In this winner take all battle, only one universe can be saved and one must die for the other to survive.
So now it is up to you. Who would win this battle? How would it happen? Do you agree or disagree with someone else's scenario? Make your argument and battle for your chosen warrior.