Editing Kyuad's Lorebook (section)

===Becoming Fell===
The initial shock of death and the subsequent realization that one has become undead is a crushing psychological blow and insanity is usually immediate, leading quickly to extreme paranoia, violent rage, and bloodlust. Strong wills may keep these overwhelming impulses at bay, but only for short periods. Fell retain its basic Intelligence and many of its memories, but as its body starts to decay, so does its mind. For every week that passes without feeding, the mental stability decreases greatly. The creature thus decays and gradually loses its intelligence and true sentience, as well as the associated memories and conscious control over its actions. As the creature reaches increasingly loses its mind, it deteriorates into more and more feral states until, eventually, it is nothing more than a walking, eating corpse. From the moment it awakens, a Fell feels a magical craving for the flesh of the living, for only by consuming the living can an undead creature maintain its foul existence. This hunger quickly becomes the driving motivation behind the actions of the Fell and continues to compel it, even after its mind has rotted away. If a Fell consumes a large meal of stillwarm flesh from the body of an intelligent creature  at least once per week, it can stave off the decay of its body as well as the rot of its mind. For every week a Fell goes without such a meal, it suffers decay and the associated loss of mental ability scores as described above. Only the flesh of living creatures with similarly potent souls can satiate the hunger of the Fell; an elf that rises as Fell could therefore survive on the flesh of dwarves or goblins but not on the meat of rabbits or bears.
Despite their horrific state, the madness of the Fell typically imbues them with a powerful survival instinct, and only the most willful soul can take direct action to destroy, and therefore free, itself. With a strong enough will an undead character can intentionally destroy itself by means of any method that consumes or dismembers its body, such as lighting itself on fire or crushing itself in a rock fall. This sort of action obviously becomes more and more unlikely as the creature’s mind decays and it loses control over its actions. Failure typically results in a period of heightened madness, bloodlust, and a sustained feeding frenzy that can last for days or even weeks.