the spectral dead

D&D has numerous varieties of ghosts. I am going to treat them as variations of the same thing. What all spectral dead have in common is that they fly, move through solid objects and are resistant to physical attacks. One idea I saw elsewhere was that there is a distinction between the spectral dead and the ghostly dead: the former is visible and consumes energy with its energy drain attacks, while the later is generally invisible and generates its own power. Pathfinder 2e introduces the generic shorthand term “shade” to refer to all spectral/incorporeal dead. Shades would include: Shadow, specter, poltergeist, will-o-wisp, banshee, ghost, wraith, allip, etc.