I can get behind this. It's also quite lore friendly.Major Tom said:An Age of Sigmar Path to Glory/Warhammer 40k Throne of Skulls scenario. 100 Champions of the Chaos gods enter the arena, but only one champion and one god can reign supreme. But it's not just the other champions you need to worry about. These are daemon worlds after all, so one has to watch the environment after all. Of course, the gods aren't above....assisting their chosen champions if they can get away with it, with relics stashed around the arena and maybe the occasional daemon incursion to make things more interesting.
balancing player interactions and the environmental factors is probably a big ask, you don't want to make the environment more dangerous than other players, but you've got 4 different play styles to work with, and you can add various sub-styles cause there's bound to be plenty of times when you have champions of the same god facing off. The ephemeral nature of a daemon world means the map makers can go absolutely nuts with the map design (within reason, you do need something that 100 people can play on).
Though I would personally just keep it Pre-Age of Sigmar and set it in the Chaos Wastes. Chaos Warbands are constantly doing this kind of nutiness to see who gets to be the Next Big Thing in the eyes of the Gods.