User blog comment:OverlordRocks/Why did you guys get rid of all the pages in the immortal beings catogory?/@comment-4824600-20160205130117

There's no confirmation that ghosts are immortal. If anything Ghoultar serves as an example for the theory that ghosts decay even more inside the Preeminant until they are non-existent. There's also nothing that confirms Skulkin can't be destroyed, leaving only the Stone Army which was confirmed in the show to be indestructible but it is rather redundant to have another category devoted just to them.