Devils
Denizens of the Nine Hells, known and feared for their proclivity for entrapping mortals in contracts by taking advantage of mortal greed and desire for power. They are cunning and have little concern for morality, however they are bound by the contracts they make, bonded to execute them by the orders of the Lord of the Nine Hells, Sakhr. Anyone foolish or desperate enough to agree to a devil's bargain should beware - they are master manipulators and only serve their own devices.
The devils inhabit the Nine Hells, named so due to being divided into nine distinctive layers. Each Hell is governed by an Archdevil: Leviathan, Samael, Belphegor, Mammon, Sathanas, Beelzebub, Abaddon, and Helel. At the very bottom of the 9th Hell is Sakhr, the Lord of Hell, who all the other devils fear, respect, and follow.
Devils are fond of rules, laws, and contracts, and exist in a strict hierarchical system based on castes. The higher the number of souls obtained from mortals that the devil posessed, the higher his or her standing, and each devil's life purpose is to rise in the ranks. The economy of the Nine Hells is also entirely based on souls and their trade. Other things (mostly precious or rare metals and other luxury items) are also used, though devils mostly see these as useful for the purpose of swaying mortals and collecting their souls. The souls are then used to generate energy that keeps everything in the Nine Hells running smoothly.
By their nature, devils are liars and manipulators. Unbound by the concepts of morality, they do whatever it is that benefits them and ultimately gets them what they want - more souls and higher social standing in the Nine Hells. That being said, they also rarely go out of their way to do somethinng evil or terrible if it does not specifically benefit them. Unlike demons, devils dislike disorder and always have a reason for doing whatever it is they are doing, even if that reason is not obvious to the mortals arond them. By command of their lord, Sakhr, all devils are bound to their contractual obligations and carry out their part of all bargains dutifully - but only as far as the contract forces them to.
Civilization and Culture
History
It is difficult to ascertain the origin of the devils, as they appear to have existed long before the material plane came into being. Various myths depict angel falling from Heaven and becoming devils, as well as humans gaining devilish traits after committing many atrocities. It is unlikely that those accounts are in any way real, however, as the biology of mortals and angels differs widely from devils or demons. The most commonly accepted theory is that both devils and demons were created by Codagh, the Harbinger of War. However, while demons served as a mindless army, the devils - gifted with cunning and devious minds - were to be his generals. Initially, the Lower Plains were united, with demons and devils existing together in a master-servant structure. However, the demons eventually rebelled, leading to what is known among the denizens of the Lower Plains as the Blood War.
With Sakhr's ascesion to the title of Lord of the Nine Hells - and with it, his rise to power equvalent to that of the divines - the Blood War has simmered down. The demons are not foolish enough to actively rise against him, fearing his retribution, while the devils do not disobey their sovereign's orders, at least not openly. Over the millenia of Sakhr's rule, several large-scale scuffles between the two sides had begun, however all were swiftly ended by either Sakhr himself or one of his closest underlings - usually with none of the aggressors left alive to complain or try again.
Genetic Descendants