Looking through the 5e monster manual I got an idea for my homebrew setting The Tidal Locked World (still working on a better name). Take these weird devils and turn them into a faction: The Solar Empire, based off of Plato's ideal city of Kallipolis. Their society is modelled to be the perfect meritocracy, complete with community-raised anonymous-heritaged children, a merit-based caste system, and ridiculously powerful devils at its helm. Less sexism though.
From bottom to top:
Lemures (The Unforged)
Little more than the melted souls and bodies to be forged into more powerful devils. Never seen outside of Tiamatris, the capital. They have no status.
They act as administrative assistants to more powerful devils. Physically weak yet usually crafty. They know a few spells which a secretary would find useful (Prestidigitation, Message, Sending).
Spine Devils (Drones)
Sentries and highly mobile shock troops. They carry incapacitating tazer-like spears. Drone-like intelligence, usually under the command of a Tiefling or a Malebranche. Unable to make judgements on their own.
People either born and raised in the Solar Empire or products of the Empire's eugenics breeding program. They have a wide range of possible positions and roles in the Empire, ranging from laborers to experts to foreign ambassadors and philosophers (the highest possible rank for a mortal).
Bearded Devils (Homeguards)
They guard important places in the Empire - birthing vats, schools, food storage. Their "beards", in addition to having paralytic effects, can act as a touch-recognition system to see through disguises or illusory magic.
(Here's where they start to get radically different)
Chain Devils (Temperate Martyrs)
Were normal people once. Then they decided to become a martyr for the good of the empire. Chain Devils take the vices and addictions of ordinary citizens within themselves, and then lock it all away with their soul-chains. They are despondent and quiet by nature, expressing little to no emotion. All hell can break loose if the chains are removed - not an easy task, as the Chain Devil can take one's want of violence away just as any other vice.
Bone Devils (Child Gusts)
Messengers and deliverers of post. "Post" includes children. Their primary task is ensuring that all children of the Empire are removed from their parents and placed in a proper school, where they will be anonymously raised and indoctrinated. Their ability to fly helps in this regard. They've got a gross little warm pouch on their underside for carrying babies, complete with highly nutritious milk sacks. They are single-minded in their approach, and shockingly good with children.
Horned Devils (Ministers of Truth)
Second highest-ranked devil, below the Erinyes and the Emperor. More than being able to fly and shoot fireballs, their greatest power is that they have perfect perceptions and insight. Perfect. Every one of them is like Sherlock Holmes times two. They can always discern lies. They can always tell half-truths from full-truths. They can tell when you're holding something back. They read the subconscious body language and analyze the micro-dilation in your eyes. They can follow your tracks from a month ago over hard ground and it rained yesterday. They can't turn this ability off. They have shelf lives.
Each acts as a sort of regional governor as part of the Ministry of Truth. They are the highest authority most people will ever encounter in their lives.
Erinyes (The Four Furies)
Each Fury is unique, a lieutenant to the Emperor, and in charge of their own division of the Empire. Their names are the Platonic Virtues: Courage, Wisdom, Temperance, and Justice. They each have the powers of Horned Devils, plus more.
Courage of the Silver Order (the Empire's army), leads expeditions into the unknown. Greatest warrior and tactician alive and a fire-tested general. His insight led to victory in the Demon-Devil wars, and he currently wages war on the Empire's behalf against the Orcs of Shadowmountain.
His ultimate power is the ability to administrate the flow of information on a regional scale, and to understand the psychology of the Empire's enemies.
Wisdom of The Order of Technocratic Wisdom, is crucially charged with acknowledging merit and assigning people their roles in the Empire. It built the being which built the being which designed the schematic for the Solar Empire.
Its power is in computation. Insane amounts of computation. It never stereotypes, as it doesn't need to. It is beyond statistics.
Temperance of the Temperate Covenant, leads the education of the young and the maintenance of the well-being of the Empire's citizens, as well as its Ambassador Corps. They are by far the nicest of the Furies, but no less terrifying.
With a simple wave of the hand they can take away your pain, your lust, your ambition. This is their greatest power.
Justice of the Ministry of Truth, finds suitable procedures for dealing with lawbreakers. She manages the Horned Devils and roots out corruption, whether internally or externally derived. She is not cruel in her sentencing, but she is firm.
Her power is as a Minister of Truth, but expanded to that which she cannot she. All must obey her judgement.
Pit Fiend (The Emperor)
Almost a god. The founder of the Solar Empire. A Philosopher King. A rebel from Hell. Looked to the classical for inspiration for a great experiment in producing a most just society. He sits on his Dark Throne in Tiamatris, pondering the greatest of questions in utter silence. His Furies direct the goings-on in the Empire, and he is only consulted if subordinates have reached an impassable disagreement.