Devil Transition

Some mortals chosen by Devils can loose there humanity and become unholy beings in the nine hells locked out of the mortal plane until summoned or using strong magics to travel from the Hells to the material plain. Humans become devils in such a way normally have to "pay" either with services, souls or other things a Devil may want any lesser or greater devil can create a deal like this but only transform the humanoid into a Devil of equal strength to the soul of the humanoid so a Peasant would be cursed to the life of a lemures while a great warrior could become a ice devil
The order is as such 1; lemures, nupperibos
Lesser Devils
2; Imps
3; Spinned Devils
4; bearded Devils, merregons
5; barbed devils
6; chain devils
7; bone devils
Greater Devils
8; horned devils , thons
9; erinyes
10; ice devils and narzugons
11; Pit Fiends, Amnizus
If a humanoid where to kill there Devil patron (contract holder) They could break there contract and there soul would no longer be sent to Avernus when they die to fight in the blood war at the same time a position would open up in the devil world and they could take there place in the Devil community if they choose to do so they would become a devil using a simple 1 hour ritual.
At this point they are a Devil and can rise the ranks all the normal ways Souls, Glory or Treachery.

Manifestation

The ritual in which someone goes from Human to devil involves 100gp of contraband magic items and a piece of Devil flesh. ending in the individual ending there own with a dagger to the heart before being reborn into the body of a Devil. Devils make a similar ritual to change form but have to use magical or silvered daggers to pierce there tougher flesh.

Localization

The nine Hells and mostly Avernes

Type

Metaphysical, Demonic