How about a constructed deck league where the players play each other’s characters? Here are three ways to do it: First way: Both players make three characters as normal. Then these characters are assigned randomly to the players. Second way: Both players make three characters. One random character from each player switches teams and goes to the other player. With the first way, it could be a decent tactic to make bad characters and hope you don’t get them. So with the first way it might be fairly random who wins. With the second way there is an incentive to make the characters good, since you are gonna be controlling two of them and only losing one. Third way: Both players make three characters. The players get to see the decks of characters the opponent made. Each player chooses one of the opponent’s characters that they want, and one of the opponent’s characters that the opponent has to take. That means there are two characters left that has not been chosen. These are assigned to the players randomly. The players have an incentive to try to make the characters evenly good, since the opponent is likely to choose the best one. When the players are looking at the opponent’s deck and choosing characters the timer goes down, like when choosing cards in quick draw.
These do all sound fun! I doubt we could get to them soon since we don't have any of the code for it yet but I'd like to get there someday ^_^