Alternate Game Mode: The Chameleon
So I've seen this idea floated around on DBD forums for as long as I've been playing about a killer that can disguise itself as a survivor. This is a terrible idea for a killer in the normal version of the game for numerous reasons. However, I've been brainstorming a way that this would work quite well as an alternate game mode. Please bear with the wall of text as I flesh out the concept.
The Chameleon: Both the survivor and killer votes for a survivor during the lobby once all players are present. All players and the killer will appear as an identical survivor. The killer has 0 terror radius and can attack using The Spirit's weapon. If the killer hits a survivor that is stationary or was performing an action within the last 2 seconds the attack will put the survivor in the dying state. The killer runs at the same speed as the nurse, but vaults the same speed as a survivor. The killer's view is 3rd person. The killer can perform all actions that a normal survivor can, up to and including unhooking a survivor (more on this later).
The killer runs the following perks:
Booby Trap Chest: You can booby trap one chest at a time. If no chest is booby trapped, reveal the aura of all chests. When a survivor opens a booby trapped chest, you can see that survivors aura for 30 seconds or until hooked.
Generator Saboteur: After successfully completing 3 skill checks while working a generator, the next skill check you fail will damage the generator by 50%.
Lack of Empathy: Unlocks potential in one's Aura reading ability. Dying or injured survivor's Auras are revealed to you when within 16 meters.
False Save: You begin the game with 3 tokens. You lose a token by unhooking a survivor. You lose the ability to attack and move at normal survivor run speed for 30 seconds after unhooking a survivor.
The killer also has the following innate traits. When the killer fails a skill check while healing a survivor, it will put the survivor in the dying state. If the killer is standing still and performs a lunge attack, the killer will injure itself. The killer can put itself in the dying state this way, but won't die if the bleedout timer runs out. The killer can heal itself at normal speed.
This game mode can only be played by solo queue. In the game lobby and during the game, player's names are not displayed. The user interface will display 5 survivor icons instead of 4. These icons are randomized every 30 seconds.
Survivors do not get to pick their perks. They have the following perks automatically. Empathy rank 1 (if the killer is injured, survivors will see the killer's aura, but it will appear like a normal survivor's aura), Windows Of Opportunity rank 3, We're Gonna Live Forever rank 3, and No One Left Behind rank 3.
The survivor perks are generally picked to encourage cooperative play, but the killer's abilities are all designed to create distrust.