I wish DBD had Insta kills like Deathgarden
Yes, I know... memento mori. The problem with that is that is not part of the core mechanic, so it feels cheap and undeserved. Also, you don't know how a match will go in advance, so you don't know in which match you should use a memento mori, and when it wasn't really necessary.
They'll never implement this, because in DG the power role is really feared, and DBD is a casual "party with friends game" and they purposefully made the power role in DBD to be weak, and have no real control over the match, so friends can have fun bullying the killer. But the thought of it is fun.
What if, as a core mechanic, you can chose to kill a survivor or keep hooking them for blood points (same as Deathgarden) if:
-A certain amount of hooks have been made (deserved), let's say, 6 hooks, you can kill 1 survivor.
-A certain amount of gens are completed (undeserved), let's say 4 gens, you can kill 1 survivor that you down.
-A certain amount of gens are done within a certain amount of time (let's say, survivors do 3 gens in 1.5 minutes at the begining of the match)
That would make the killer have control over the match, if it's getting out of hands, or you're being gen rushed by a coordinated SWF, you can "slow the game down just a little bit" by removing one survivor and tilt the balance to your favour, or you don't care and you'll go for the extra BPs.