Killer sugestions : SAW chapter 2 or Spider killer
Saw chapter 2 :
Make a trial like the second movie.
Killer : Allan Gordon. Pretty weak and slow m1 killer but very strong traps and additional objectives.
5 of 7 gens are locked and you have to find keys around the map to unlock gens.
1 key in a random locker arround the map.
4 keys in 4 different traps. Traps could be inspired from the saw 2 movie ( seringues hole, razor box, furnace, chest enigma ).
Traps should be lethal with their own death animation or failling the traps could make you enter the dying states.
Killer should not be able to interact with survivors attempting a trap and survivors should receive a 10 second timer immunity after escaping the traps.
Adds on would be to make traps deadlier, longer, harder or have specific rules for survivors/traps
The idea is to make something different and thrilling that would allow fun for both side. When traps are done, allan gordon would be a basic m1 killer without power.
Spider :
A spider that can walk on wall, jump on survivors, can make spider web by blocking gens, doors, pallet, path and with a venomous bite
Map could be something new like a labyrinth made of rock tunnel