User blog comment:Silver-Haired Seireitou/Supernatural Creature Project/@comment-18812574-20140509044915/@comment-1493741-20140509052803

People forget the Bounts cause they suck. :P

Given the way Souls work in Bleach, zombies/Jiangshi/other forms of undead could be Jibakurei that are stuck in some sort of purgatory between being bound to the Human World and migrating to Soul Society, the purgatory prevents them from degrading into a Hollow but obviously keeps them from passing on to the Spiritual Realms at the same time. A rare negative possibility/flaw within the Chain of Fate perhaps?