Limited time 10 player mode. (Suggestion.)

8 survivors, 2 killers. Imagine the interesting circumstances. It would allow for greater complexity in how you prioritise goals, because with 2 killers and 8 players, things would be mad. There might need to be an additional generator, but I think the game would work as it currently does, even with double the players.

Also, what could be interesting, is the other killer being targeted, or able to be killed like the players. So you'd need to avoid the other killer like in the traditional horror crossovers. It could increase the tension in the game. Also, I could see the obsession feature knocking a killer down a peg or two, for example, The Nightmare getting an obsession on The Pig (that does work with the movies, too but that's not related.) causing the bear traps to be harder to place in the right spots and the game to be rushed.

And of course, the comedy potential of having one of the more supernatural killers felled by a simple knife. And hurting a fellow killer would mean the survivors get an advantage too, like in Freddy vs Jason.

This of course fits in with the lore, because why not let killers have their fun? As long as there are deaths and The Hatch isn't opened, all that, The Entity is winning, right? I'd love this, others would love this and people just want to see the killers together in game, nothing more. It's the half the fun of crossovers and let's be honest, you won't find interesting character interactions in a horror crossover movie really, and they never come round in a video game, even the Marvel vs Capcoms.