The Marvel and DC Universes has been brought into conflict. Two impossibly powerful gods have forcibly merged the two universe together. Known only as the Brothers, their goal is this: to determine once and for all which universe is better.
The Brothers have threatened to destroy both universes, unless all of Marvel and DC's superbeings participate in a dangerous contest. The Brothers will summon two superbeings from each universe and teleport them to a random, deserted location. Once there,
they will do battle until one of them has been immobilized for ten seconds. The loser will then be transformed into a loving sex slave, dedicated to serving their former rival. If the winner is straight, then the loser will be given the appropriate gender.
Once the contest is over, the universe with the most losses will be turned into a sexually charged parody of itself, enslaved to the will of the winners for all time.
The first match is about to begin, as two heroes prepare to battle for the fate of all they know and love...
(A/N: This was written in a hurry. While I won't change any essential details, I'll probably come back and expand this when I have time. If it wasn't obvious, this was based on the 90s crossover. I encourage you to make up your own matchups.)