1) Your OC meets Cheri Bomb at a nightclub in hell and ends up befriending her for a night of wild fun
2) Your OC is one of the sinners staying at the hotel and is friends with Angel Dust. One night, your OC catches him sneaking out of the hotel to go have a chaotic night of fun with Cheri Bomb and he invites your OC to come along.
3) Your Own Idea (must be explained and approved)
