I went solo today after reading how to do so on the forums. Didn't realize when grouped that you COULD go down another level! So I scoped out as far as I could go.
I wound up in a graveyard level. Tons of skeletons, fairly easy to kill, seemed like awesome loots for me!
But these insane red spirits show up on a regular basis. I can attack them and eventually they become just a red dot, but after a period of time they will reanimate and hunt me down. As soon as I got trapped in a room and 3 of them showed up in addition to the nasty surprises programmed for the location, I wound up dead.
Is there some way to perma-kill these spooks? Or are you just meant to make a mad dash through those levels?
Some people argue that they don't revive, more just show up in their place, I don't know or care because its the same result.
You can't finish them off forever in either case, you either kill the ones following you and take your few minutes of peace, or you do whatever you can to distract them and run.