Neverwinter Nights 2 Persistent World BGTSCC Discussion Forum
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With regards to demons in particular, the Fiendish Codex I has this to say about their "life cycle:"Souls can reside in the city for up to a tenday before a divine servant comes to collect them, often completely clueless to the fact that they are dead. During that time, baatezu are allowed to inform souls of their state and bargain with them. Souls are offered the chance to become devils themselves, usually starting as a lemure but having the chance to advance through the devilish ranks, possibly even becoming a pit fiend. This is the main way baatezu propagate. The prospect of becoming a devil may seem abhorrent to good-aligned mortals but those who follow evil deities and those who fear what awaits them in the afterlife are much more likely to take up the offer.
Fiendish Codex I, pg 8 wrote:The Demonomicon insists that all demonspawn begin as manes (larvae demons) or other lower-order fiends and, over the centuries, progress up a ladder of power and evil until they become dretches or rutterkins at the whim of a powerful nalfeshnee or demon prince.
Once these demonspawn join the hosts of the Abyss, they then slave away in servitude and fear, hoping to go unnoticed by their masters -- for notice means torture and pain -- while perversely longing for the spark required to transform them into a higher-order demon. [...]
[...] While the Black Scrolls of Ahm do not refute the Demonomicon's position on the order of demons, Tulket nor Arhm disagreed on two important points. First, he wrote that demonspawn could instantly become any level of demon, depending on the "desires" of the Abyss itself. Second, he asserted that the "ladder" of demonkind is more of a circle (though his picture of the demon hierarchy looks more like a drop of blood than a circle).