The Devils Ultimate

"Do you understand our burden, mortal? Of course not. You believe things on a scale of black and white, good and evil. You don't even understand how wrong you are."

Credits to Dominik Mayer on ArtStation for the incredible cover art!

Standing at the pinnacle of the impossibly complex hierarchies of Iduran, the Hellish Realms, the Devils Ultimate is the name given to the archdevils that control Hell and its vast legions. Their goals and methods may vary, but the Devils Ultimate are all united in ensuring the prosperity of themselves and their supplicants---and ensuring that nothing like Narvox's conquest of Iduran ever happens again. To this end, they often reach across Yophas and attempt to pull mortals under their sway, forming pacts and deals to create warlocks, illriggers, and more.

Xhor'thras, the Monarch of Coldfire

Ruler of Iduran, master manipulator and respected---and feared---by the other Devils Ultimate, Xhor'thras rules with an iron fist. She was dethroned by and forced to serve at the right hand of Narvox. In the wake of the Reckoning, she holds a great contempt for all the gods but most specifically hates Narvox.
She learned a great many things from the God of Domination and uses his tools in her own work now. Despite her hatred for Narvox, Xhor'thras also respected his power. In this and all things, she is duality made manifest.
She can shapechange and lie like no other, yet prefers her true form and an honest contract. She is monarch and protector of Iduran, and dominates whoever she needs to grow the power of herself and her realm. She is selfless and selfish, willing to do whatever she must to protect Iduran at the cost of all other realms, yet her constant battle within Mathrak against the hordes of Ix'akroth defends all of Yophas.
To serve Xhor'thras is to serve a thousand masters, for the personalities and faces that the Monarch of Coldfire will invoke to manipulate are endless. Yet, they always back a single directive: to undermine any enemies of Iduran in life---be they servants of Narvox or holy retributors of Yamma---and then reinforce Iduran's defenses in eternal service after death.
Appearance. Xhor'thras' true form is that of a humanoid woman, standing nearly twelve feet tall. Her skin appears like cooled magma, but the cracks and "lava" are a deep, cool blue. Two horns of unworked obsidian curl from her forehead, and wings of ashen shadow roil from her back. She is most often clothed in opulent dresses or suits of black trimmed with gold.

Azreman, the Monarch's Arm

Xhor'thras' enforcer, Azreman is the single greatest combatant in infernal history. He is a wrathful but cunning devil, and he is nothing if not honorable. He seeks out combatants who can match him, a search that almost always leads him to disappointment. Few are those who can last against Azreman, and fewer are those who can challenge him.
To serve Azreman is to serve combat itself. He will not grant power, but he will grant knowledge; invoking Azreman is invoking an eternity of battle experience. Those under Azreman have their own strength and an endless font of wisdom in combat to draw on---assuming Azreman finds them worthy of such knowledge.
Appearance. Azreman can appear in whatever size he must to face a combatant one-to-one, but he always appears as a muscular, red-skinned devil clad in an immaculate white and gold plate that is inscribed with countless infernal runes of power and protection. He wields Orezmir, a shard of glass that can shift into unbreakable weaponry of any shape and make as Azreman wishes it.

Rarrimer, Iduran's Lecher

Creator of succubi/incubi, Rarrimer is the androgynous king of sexual contracts and manipulative negotiations. Sex has power, and Rarrimer knows this. He is lustful and impassioned but willful and intelligent. Some even claim that he is the corrupted child of Valereth themself. He is a master manipulator, and understands all the different dials that make people tick---and how to turn them as he needs.
To serve Rarrimer is to seek that same understanding of manipulation. Whether in lechery or lies, servants of Rarrimer grow their strength through collecting servants and manipulating others. Spies, deceivers, and manipulators have much to gain from dedication to Iduran's Lecher.
Appearance. Rarrimer is a muscular devil of deep purple skin and stark black, straight hair. Red horns curve back and over his hair, and his eyes are like solid jewels of rich violet. Rarrimer rarely wears anything other than a single, thin loincloth, which barely covers his intimate areas. He carries himself with confidence and lust, radiating sex and power in all he does.

Xul'gith, Contract-Keeper

Titanic banker and money-counter of Iduran, Xul'gith keeps track of the countless contracts signed or given by Iduran's inhabitants. She is a master organizer and planner, and the most shrewd businesswoman in all of Yophas. She sees all of Iduran's logistics and plans for economic growth on the span of decades and centuries rather than "quarters" and "fiscal years." Similarly, all contracts---even those from her fellow Devils Ultimate---pass under her vigilant eyes to ensure they hold up to Iduranith law and customs.
To serve Xul'gith is to seek the power of intellect and planning bordering on prescience. Supplicants of Xul'gith range from diplomats and ambassadors seeking the ability to forge impeccable treaties and contracts to businesspeople who want profits and power above all else.
Appearance. Xul'gith is a fortress-sized mass of roiling black-green tentacles and bright red eyes. Her body is seemingly formless in shape and her tentacles and eyes are countless in number. They spill out and bubble like ichor, reaching the "bounds" of Xul'gith's bodies before roiling back into the mass. Her eyes are all-seeing and her tentacles allow her to manipulate the endless tide of contracts and ledgers she manages within her citadel.

Ral'garan, General of Flame

Leader of Iduran's endless legions, Ral'garan is an unparalleled commander and tactician. He nearly rivals---but never will truly match---Azreman in martial prowess, but that rarely bothers him; Ral'garan is much more concerned with the war, not the battle. Ral'garan balances the movements, logistics, and battle outcomes of a war fought on endless fronts against an endless enemy by an army that may seem endless but is not, in fact, infinite. Ral'garan commands Iduran's legions in the impossible: maintaining a stalemate across an entire plane against a force that is truly, completely unlimited. And he has done it for millennia.
To serve Ral'garan is to serve War. He can grant great knowledge of tactics and battle cunning, but he never provides answers. He gives his servants the perspective and information they may lack; it is still up to them to forge a victory from it.
Appearance. Ral'garan is the original pit fiend. He stands nearly twenty-five feet tall, all blood-red scales and measured fury. His fangs are great on his snarling face, as are the massive bat wings that drape him like a cloak. He is always clad in his full dragon titanium plate, which he had forged after being defeated by Narvox when he usurped Iduran's legions in the Reckoning, and keeps Hordebreaker---his dragon titanium, black-crowned mace---at his side at all times.

The Kingdoms of Iduran

Iduran is split by four massive kingdoms, each ruled by a Devil Ultimate (Azreman doesn't rule a kingdom, as he is busy being Xhor'thras' will and has no interest in boring things like gold and kingdom management). Those kingdoms and their rulers are as follows:

• Ivelan. The fortress-empire of Ral'garan, Ivelan holds the Burning Gates and almost all of Iduran's military-industrial complex. It is a land of blistered mountains covered in foundries, mines, and fortresses.
• Aidrocuria. The kingdom of lechery, Aidrocuria is the smallest and densest kingdom. It is ruled by Rarrimer and houses the entertainment cities of Iduran. It is the most diverse kingdom of Iduran, as it is the sanctioned kingdom of planar tourism and travel within Iduran.
• Uloxirene. Economic powerhouse of Iduran, Uloxirene is the largest kingdom of Iduran. Xul'gith rules this kindgom, and Uloxirene's many baronies provide the food, resources, and trade that keeps the massive wheels of Iduran turning.
• Xhorin. Land of rulers and masters, Xhorin is the smallest kingdom of Iduran. It is ruled by Xhor'thras and lies at the heart of Iduran, defended on all sides by the realms of the other Devils Ultimate. Behind Xhorin's titanic walls of black iron, the aristocratic elite of Iduran train, deal, and plan.

Save Xhorin, these kingdoms are crisscrossed by baronies where lesser archdevils run affairs. The majority of Iduranith devils work and live in these kingdoms, despite mortal perceptions that all devils are conscripted into Iduran's endless legions; while the legions of Ivelan are vast, they are only a small---but powerful---portion of Iduran's population.

Serving the Devils Ultimate

Mortal servants---willing and otherwise---of the Devils Ultimate can take many forms. They can be powerful knights, paladins, and anti-paladins (known as illriggers, to some), who invoke the will of their fiendish masters to dominate the battlefield and decimate their enemies. 
Others are arcanists who form pacts with the Devils Ultimate to gain access to devilish magics, all for the low, low price of their soul after death.
Others still are deceived: clerics believing to serve a vengeful aspect of their god, only to actually serve Azreman, or an indomitable barbarian who invokes a particularly inflamed rage on the battlefield. The methods of deception vary, the outcomes are myriad, but the end result is the same: power in life and an unwitting service in death.
Pacts with different Devils Ultimate and their subordinates will always vary, some drastically and some minimally, and every single contract is unique in some way. The only rule is this: a pact with a devil is forever, and to break them is to invoke a fiendish wrath that will reclaim your soul by force more often than not.

Thankful to Kaedo

Strangely enough, many devils in Iduran pay respects to Kaedo regularly. This is in large part due to his role in freeing them from Narvox's chains during the Year of Divinity's Fall, but as the centuries have passed, many forgemasters and quartermasters in Iduran have started wholly worshipping Kaedo so they may forge better equipment for Iduran's legions.
In acknowledgement of Kaedo's help during the Reckoning, Xhor'thras allows this worship to continue freely.