If there are no villains, then we can do one of the other ideas instead.
For example: VII - we will have heroes and villains, so there will be an obvious good/bad battle. In addition to that, if people want, there can be a hero vs. hero battle, a villain vs. villain, and so on. It is all up in the air and can happen rather spontaneously. I just would like everyone to be on the same page, structure-wise.
So yeah, if there are no villains, then heroes can battle each other, if the cosplayers so desire. Nothing has to happen, just if people want to. If none of those heroes want to fight each other and there are no villains from the game, then we will just skip that game in the Game-Specific, and they can participate in the Crossover, if they want.