Followup questions! Let's say a guy has a chance to examine a doppelcorpse at length, having previously examined the corpse of the person being impersonated. (John spends a normal amount of time looking at corpses.) Will he be able to notice any differences other than a general "human+" makeup of blood and bones? Does the process of the doublecorpse rotting into a skeleton seem like the same rot they weaponize against PCs? Do they have a different "death-energy signature" than the people they're impersonating, eg. they're soaked in death in a way normal PCs aren't?