This is a battle where any amount of people can just jump in and let loose without worrying about any serious logic or competitiveness. The first main rule is that you cannot do anything that will automatically kill your opponent no matter what (without first leading up to it in a fair way) or do anything else that would spoil the fun. You're not trying to simply defeat your opponent (even if that's the character's motivations), but rather trying to have maximum fun and epic-ness for everyone involved. That being said, even if your character finds themselves cornered and probably couldn't do a certain dodge, if it looks cool and can be hand waved somehow then feel free to do so. You don't have to post a character sheet before joining, just jump in and explain all relevant information in the IC if you don't feel like posting it here in the OOC. You don't have to reveal all of their powers, which will just be revealed in time and could help get you out of sticky situations. 

The second major rule is that if characters of different power levels show up then you shouldn't bully weaker characters if they tell you not to. Remember, we're here to have fun and not to crush people as soon as possible. Therefore, if you want to send out a certain power level character you should first see if anyone is around who wants to fight at that level. I imagine most people powerful enough to destroy a village or something, which offer a good variety of powers without going too overboard, even if a little overboard is really cool for this battle. They will all be fighting on the same battlefield at the same time, just in slightly different areas.

You will not be limited to number of characters, so you can come in with numbers rivaling an army if you feel like it and it won't spoil the fun for everyone.

Anyone interested in joining?