Michael Myers and Leatherface make the most sense for slashers.
Why stop at just horror slashers? This type of gaming would be fantastic with Alien, Predator, Terminator, The Thing
I'm glad someone mentioned it above, because the Thing would be amazing All 8 survivors trying to keep the frozen research station running while looking for the Thing and killing it before it escapes to the real world. As the Thing, stalking individuals and avoiding detectors and flamethrowers, while also playing along with the plan to avoid suspicion. Maybe even the ability to infect 1 player making it 6v2. Customize the types of attacks and forms you can take.
Alien would work like the Isolation game, but 7 crewmen instead. Motion trackers, flamethrowers, trying to make to the escape pods or calling for a marine pickup. Same idea Thing, get 1 player near a facehugger and a few min later, the player hatches into a new xeno, making it 6v2. Customize color, skin, armor type (warrior or drone) dog, human or Predator host, hell make some new hosts up?
Predator vs 7 special forces soldiers, limited ammo, traps. Call in the chopper to escape, kill it or repair a boat by the water. Mud can work as a temporary camo from Predators thermal vision. Predator has the ability to run faster, jump higher, climb trees and of course have invisibility. Not to mention all the cool Predator weapons. You could have the original predator, the berserkers, customize faceplates warpaint, armor and weapons
Terminator vs 7 resistance soldiers in the ruins of a big city, trying to set up traps or repair a hefty weapon, or a truck to escape, maybe trying to reprogram a damaged Terminator to fight for you for a little while (much weaker than the one hunting you) trying to download and send info back to HQ, coordinate to get a resistance air strike in to help, etc. Different models of terminator T-800, 700, 600. Different types of skins, battle damaged or not, unskinned endoskeleton even.
There are a lot more concepts where this type of game could be very fun to play.