An Archfiend is a particularly powerful fiend, usually a creature that rules over one of the fiendish planes or has a fiendish army at their disposal. There are 10 Archdukes of Hell, an unknown number of Baernoloths and possibly an infinite number of Abyssal Lords, though only 10 really worth noting.
Each abyssal lord is a demon that has a realm on one of the layers of the abyss. They either scheme against each other, throw their armies into the Blood War or try to manipulate events on the Material Plane. In a theoretically infinite Abyss there are theoretically an infinite number of Abyssal Lords. only 10 Abyssal Lords regularly interfere in the affairs of mortals and these are:
- Baphomet: Patron of Minotaurs
- Dagon: Worshipped by many underwater creatures.
- Demogorgon: Currently hold the title of 'Prince of Demons'
- Eltab: Lord of the Hidden Layer. Has been a major influence in eastern Faerûn.
- Graz'zt: Probably the most powerful of the Abyssal Lords.
- Kostchtchie: Corrupts Frost giants to worship him.
- Malcanthet: Attempts to corrupt followers of Sharess in competition with Graz'zt.
- Orcus: Lord of the undead, enemy of Kiaransalee and patron of Zhengyi.
- Pazuzu: Interested only in the corruption of mortals.
- Yeenoghu: Patron of Gnolls.
After Araushnee was cast down from Arvandor into the Abyss, Corellon Larethian cursed her into becoming the Abyssal Lord Lolth. Lolth has since regained her divinty and left the Abyss, shedding her mantle of Abyssal Lord.
The archdevils have a strict hierarchy. The deeper the layer that they rule, the higher their rank in the eyes of the other devils. Ancient lore tells of devils having once been angels but they left the holy ranks to rule over the Nine Hells. Asmodeus led the migration and has since ruled the 9th and deepest layer of Hell. Things remained constant for a long time, but relatively recently, the order of things in Hell has changed at Asmodeus' direction. The archdevils are now as follows:
- Bel: Lord of Avernus. Overthrew the former ruler of Avernus. An excellent battlefield tactician.
- Dispater: Lord of Dis. Cunning and manipulative, with an affinity for creating and destroying metal.
- Mammon: Lord of Minauros. Greedy and lustful, unusually untrustworthy.
- Belial and Fierna: Fierna rules Plegethos but her father Belial, also an archdevil, resides there as well.
- Levistus: Lord of Stygia. Trapped in a block of ice by Asmodeus.
- Glasya: Lord of Malbolge. Daughter of Asmodeus. Took control of the layer after killing the Hag Countess.
- Baalzebul: Lord of Maladomini. Arrogant and ambitious, was cursed with a wretched body by Asmodeus.
- Mephistopheles: Lord of Cania. Master of fire, despite his icy demesne.
Asmodeus is the lord of Nessus and was, for as long as any record suggests, an archdevil (though apparently, he did once posess the mantle of godhood). When Dweomerheart disintegrated, Azuth was flung into Nessus where Asmodeus stole his divinity thus shedding his archdevil status.
Gargauth has achieved godhood and is no longer an archdevil.
While Araushnee was banished to the Abyss by Corellon, her ally, the fallen Solar Malkizid was banished to Baator, where he soon became an archdevil. Eventually, he angered Asmodeus and was banished from the Nine Hells. He travelled to the Blood Rift and became a lord of the Yugoloths, therefore, he is both an archdevil and a yugoloth.