Despite the large number of dead bodies from the Cataclysm, there have been far fewer than usual attacks from random undead. There are also reports of terrifying new Incorporeal Undead. An unnamed source from Sanctuary confirmed encountering one of these horrors while in a crypt, and stated that the creature was more intelligent than the average undead and also resistant to normal weapons, thought it seemed blinded by rage. It’s unclear if the strange behavior and decrease in random attacks from ghouls is linked to this new type of undead, the Cataclysm, or some other undetermined factor.
Volume 1, Edition 13
-Marius of the Leaf