Ok so I'm making it so player vampires are immortal unless beheaded or perhaps burned to death. NPC vampires too, but once I get this working, that should be easy enough.

I was thinking of copying the decapitation perk, and making the clone of it called vampire decapitation, and then change the % chance to 100%.

The player will be set to essential, (as well as all vampires). Then when the player is in the knocked down state, I would add to npcs hostile towards the player the special vampire decapitation perk, and then they would cut off the players head. I suppose at some point in the script, I would set the player to non-essential, like if I could test if the player has been decapitated or is wearing the decapitation armor art or something.

I'd probably make it so low level dumb npcs like bandits wouldn't even know to cut your head off, until you get up 3-4 times, but maybe higher level enemies like necromancers might know right away that a vampire needs burned or their head cut off, and I'd give them the perk right away. My goal is to give the player an extra chance or two to defeat mortals, and make fighting other vampires harder by them coming back to life over and over again until you cut off their head.

Or is there an easier way to do this? Like is there a way to force two actors to play a kill move?

Any insight towards kill moves and decapitation would be helpful.

The problem is this:

You can check on a character with IsInKillMove and decapitation is a kill move, but from my understanding the only way to recognize decapitation is if the character equips the armor piece DecapitatedHead after the OnDeath event, but I don't know if essential creatures would allow that...