Honesty I think this fits the most with the bad ending of the game, when Cuphead and Mugman get their souls taken by The Devil and they essentially become his minions.
With this rat named Devil yeah i bet but with the real Satan i think he wouldn't, Satan doesn't need a dumb pitchfork to fight a bunch of antropomorphical cups with magic powers delivered from some sort of dumb mythology folclore adaptation. Unlike Indie Cross's Devil or Cuphead's Canon this fallen angel like any other can't die nor be warped or manipulated by some dumb kids.
With his friends happy and content they set off in to the sunset .... YOU REALLY THOUGHT I WOULD JUST LET YOU LEAVE LIKE THAT oh no were not done yet not even close now that I have your soul your in for a HELL Of A TIME HAHAHAHA
