Devils

Devils are the native denizens of the Plane of the Nine Hells, sometimes called Hellions. They are a species of ambitious and vengeful people who act exclusively out of self interest.
Souls are the primary currency and social currency of the Nine Hells, their entire society is structured around acquiring souls. This is almost exclusively done through bargains and contracts with mortals in exchange for their soul.
These contracts are divinely binding and are capable of offering almost anything a mortal can desire. A Devil can not trick a mortal into making a deal, they must be consenting participants, but that doesn’t mean they have to fully understand the contract. This means Devil contracts are commonly filled with complex language or secret appendices.
Souls are also so valuable to Devils because their main purpose is to be used to create more Devils. Mortal souls are twisted and tortured over years, eventually transforming them into newborn Devils.
The Devils are at the front lines of the Blood War, a never ending war on the layer of Avernus against the Demons of The Abyss. The Hells protect the rest of the Universe from being overwhelmed by the spawn of The Abyss, striking down down the infinite waves of Demons since the early years of creation. Because of this Devils despise Demons more than anything else in creation and are enraged if they are ever confused for one.
Ancient texts suggest that Devils were originally created to fight off the Demons of The Abyss, they were to be the army of the Gods, but they were far too ambitious and were not to be trusted. It is speculated that Devils were designed off of Demons, but suggesting that is a death sentence.
Language: Devils speak their own language of Infernal, which is almost exclusively spoken by Devils.

Biology:

Devils do not need to eat, drink, sleep and they do not age. Most Devils are not capable of reproduction, with only Archdevils capable of creating offspring.
Devils don’t have a concept of Gender and can change their appearance to be masculine, feminine or androgynous at will. Though most will stick to their favoured form.
Unlike mortals, Devils do not possess souls or free will. They have a set and strict identity and are incapable of change. If a Devil dies outside of the Nine Hells, they return back to the Hells, beginning a long and tortuous process or reforming until they return to full strength with their memories intact. Devils only die permanently if they are killed within the Nine Hells.

Hierarchy:

Devils are beings of order, they have a strict class system. Devils can be "promoted" or "demoted" and are forced to obey orders from their superiors, even if they dislike them. The punishment for failure or disobedience is demotion, this means Devils hate defeat and humiliation, they often develop a vengeful grudge at those who wronged them.
As a rule, Devils can not be promoted until another is demoted, meaning Devil's relish in the failure of their peers. This also means the Hells are filled with intrigue, doctoring reports and backstabbing.
The Hellish hierarchy system is exceptionally complicated, with many levels. Every Devil desires to become an Archdevil of one of the nine layers of Hell and to even overthrow Asmodeus. The Hierarchy can be simplified to the following:

Lesser Devils:

These are usually the footsoldiers of the Hells, they are ordered around by their superiors and are tasked with the worst jobs.
Lesser Devils tend to be quite weak, like Imps, and are unable to form contracts or make pacts.

Greater Devils:

These are the commanders and generals of the Hells, bearing the title of Duke. They are responsible for ordering around Lesser Devils and scheming against the Archdevils. They have a lot more freedom than lesser Devils and a lot more chances to fail.
Greater Devils are usually a lot more powerful than your average mortal, like Pit Fiends, and can be found forming contracts for mortal souls, but can not make pacts.

Dukes:

These are the generals of the Hells, they are responsible for ordering around Greater Devils and scheming against the Archdukes. There are twenty three Dukes in total and they usually serve an Archduke, leading large operations on their behalf.
Dukes have a lot of political power in the Hells, they are capable of forming contracts for mortal souls and can be found making pacts with mortals, power in exchange for service.

Archdukes:

The Archdukes, sometimes called Archdevils, are the most powerful of all devils and are at the top of the Hierarchy of the Nine Hells. They are Quasi-Deities, a vicious and backbiting group made up of the Hells’ elite Devils. Archdevils are the most efficient at forming contracts for mortal souls and can be found making pacts with mortals, power in exchange for service.
Each Archduke is a leader of one of the Nine Layers of the Hells, with Asmodeus themselves ruling the final layer of Nessus. The Archdukes only take orders from Asmodeus themself, they can commonly be found scheming against Asmodeus and each other.
There are nine Archdukes in total, each representing one of the eight sins of Celestia: Gluttony, Lust, Greed, Envy, Wrath, Sloth, Vanity and Pride.

Genetic Descendants

• Tieflings

Origin/Ancestry

Fiend

Lifespan

Immortal

Geographic Distribution

• The Nine Hells

Patron Deity:
Asmodeus - Archduke of Nessus