A Quite Place
I believe an interesting killer to add would be none other than the Death Angel from A Quite Place. This killer could have a lunge attack similar to demogorgon, but it's own unique ability would be to "hear" any auras around the map from survivors making noise sprinting, opening lockers, repairing generators, etc.
As for perks:
Electrical disruption: when the killer is near a generator during a chase that has repair progress, that generator loses 2% progress over 10 seconds. Cooldown 5 seconds.
Auditory Hunter: Survivors footfalls are more easily heard providing audio ques feeding into your bloodlust granting haste of 4% when within a 24 meter range of a survivor.
Deaths embrace: when putting a survivor into a dying state for a second time this perk activates causing the survivor to suffer the broken status effect for 90 seconds and bleed out 25% faster. Perk deactivates after 90 seconds of broken status. Cooldown 60 seconds.
Special items: cooking timer
The special item can be used to throw off the killers ability to track you when using special move. Timers will ring for 20 seconds once activated and will have to be reset to use again. Note: the killer can break these and there are a limited amount of 12 on the map so use wisely.
Add one could be things that increase lunge attack range, the auditory special to have auras displayed for extended durations, and reduction of perk cooldowns.
Hope you enjoy and would like to see this come to fruition.