Do timed insta kills fail the moment the target disappears or do they all continue until the timer is up and the target is not there before failing? Because I know with soulless even if you leave then come back before the timer ends, you'll die.

If you're in the room for every tic, you die.

Instas have certain 'ticks' (chasm has one at six seconds and twelve seconds, the second one being death) where things such as target presence, afflictions, etc. are checked. Judge has one every 2.5 seconds (I think).

Isn't it one every four seconds? Start, at 4, at 8 and death at 12.