Okay here me out, I'm listening to this song and I can’t help but think how interesting it would be if there was a Batman game where in one route, you'd get batman successfully turning joker to the good side and he becomes Batman's partner in vigilante and basically takes down bad guys and doesn't kill them and in another route, you’d get joker successfully turning batman to the dark side and he becomes jokers partner in crime, the batman that kills. Both of their rebirths would be the same as the other. Joker would be reborn surrounded by bats and Bruce would fall into a vat of chemicals. This new version of batman due to his now pale white skin would look vampiric and his outfit would reflect this transformation into this killing vampire bat monster (who only kills bad guys of course). The joker would still have his iconic outfit, but bats would be incorporated into the suit along with a utility belt. Within the game, choices can be made where the joker may fall back into a life of villainy or where batman will fall back into a life of vigilante, but the game can end with neither of those things happening.