In the console I checked if he was essential and he is. I tried setting his essential to 0 (and I used BaseID and not RefID if you are wondering), but it didn't change him from having essential at 1 to essential at 0. Using the kill command through the console obviously wont work without changing the essential to 0 first.
I don't know if this would effect anything but I do have many mods installed.
Can anyone help me please?