I've been thinking about something lately. You guys ever play custom games in Halo? You have crazy amounts of customization options and you can really make the game drastically different in many ways. I thought this would be a cool idea for private matches in Injustice or really any fighter. Also like the Halo games, if a custom game ends up being REALLY GOOD then it would be put into matchmaking. They could figure out how to implement that. Not that it would ever be added into Injustice, but it's something to think about.

Things could be changed like... whether or not certain moves to chip damage. I think it would be cool to try no chip damage on normals. You could adjust player movement speed and gravity for jumping. Also player speed. Change overall damage output. More or less health. Interactables, Supers, transitions, all be able to be enabled/disabled. Time limit options. Other various settings that the player could decide. They could also have an arena editor/maker where you can create your own. Also take the existing ones and add or remove interactables, or place them where ever you want. I think Fortress of Solitude would be cool with one spike ball in each corner, no laser or doomsday interactable, no transitions. It would be super even.