IF... all Dimensions / Universes Possess The Same Level Of Power (see story and trailer at home page) and that Power was distributed amongst its Fighters WHO WILL WIN? (i.e. in this scenario the power rating of the most powerful beings in every universe are about the same... Superman's overall powers will be comparable to Hulk, Shao Kahn, Shin Gouki, etc... get it? It will all depend on skill, strategy, and the fighters' unique abilitites)
Special Note: Site is run by single author. Many games are available and they are all high quality games. Most games are in HD. This site is pretty active and the author often releases new games or updates. This is a good site to go to if you're looking to add characters and stages to your existing game as well. Just download his games and get the desired characters and stages.
Special Note: While this site only offers downloadable characters, they went deep and are offering a huge collection of characters from pretty much all fighting games ever made and even some non-fighting games.