Fan Casting Justice League x Avengers: the Animated Movie

Krona, an exiled Oan, travels across the Multiverse and destroys universes seeking the truth of creation. When he arrives in the Marvel Universe, the Grandmaster—wanting to save his universe—proposes that they play a game. If Krona wins, the Grandmaster will lead him to Galactus, a being in that universe who has witnessed creation. If he loses, Krona has to spare the Grandmaster’s universe. Before choosing the players to participate in this game, Krona demands to swap champions, so the Avengers (the Grandmaster’s longtime adversaries) will represent Krona while and the Justice League (from Krona's home universe) will fight for the Grandmaster.