i haven't seen a glitch like this before, so it could be the OpenGL/CMD issue? if you don't find the demon quickly enough it does instakill, so it might be that also. sorry ur having this glitch!
I use CMD to open the game because of a problem in OpenGL that simply does not allow the game to open. Using CMD I force OpenGL to work and run the game normally. And about the Demon, I'm well aware that I need to be quick to lose him, but when he jumps at me, it's automatic, I die without being able to react XD