Killer interactions.
I just was talking with someone about the Spirt. We thought it was funny how she would stroke the side of someones face when pulling them from a locker and thought... what if the killer could do creepy stuff like that all the time? Like, on a downed survivor if you have something planned for them just act super creepy to them. Or just wave to a survivor showing they are next on your list of survivors. Just minor interactions with survivors to unsettle them more or be friendly until later.
Comments
More emotes for survivors or killers would probably cause more toxicity.