Aoe2 hidden cup inspired duel tournament where people don't know who they are playing, i.e. I sign up and get assigned number 11, herishey signs up and gets assigned number 37 and so on. You randomise the bracket like you normally would, but everyone has to use the default in-game character, the generic blonde guy.
At the end of the tournament you could give out the list of players and their corresponding number.
I think it could be quite entertaining, although the simple task of joining the server with your assigned number and a default face could prove difficult to some
and herishey would leak the list of players 3 hours before the tournament
