Concept art done a few years back for the licence Werewolf: The Apocalypse (World of Darkness).
Possessed guards with a chance of mutation when sustaining damage, unlocking a special attack/changing behavior pattern. Umbra vision is used to detect which parts are susceptible to mutate.
"Fomori are a type of Possessed aligned with the Wyrm. Usually the work of full-body Bane possession, a fomor is corrupted in mind, body, and spirit."
Follow-up to this:
https://www.artstation.com/artwork/aGLmdL