Asmodeus

(a.k.a. Supreme Master of the Nine Hells, Lord of Nessus, The Lord of the Ninth, The Cloven, Old Hoof and Horn, Lord of Lies, The Archfiend, The Raging Fiend, Prince of Evil)

I literally sit beneath eight tiers of scheming, ambitious entities that represent primal law suffused with evil. The path from this realm leads to an infinite pit of chaos and evil. Now, tell me again how you and your ilk are the victims in this eternal struggle.

— Asmodeus addresses the celestial jury, from The Trial of Asmodeus

Open worship of Asmodeus began roughly a century ago when small cults with charismatic leaders sprang up in the aftermath of the Spellplague. That catastrophe left many asking why the gods were angry or had abandoned them. To those questioners, the faithful of Asmodeus provided answers and a god who would forgive all their faults. Still, for the next few decades, the Cult of Asmodeus struggled for acceptance.
In the beliefs of the people of the North—which coincide with many tales told by dwarves, elves, and others—Asmodeus is Lord of the Ninth, the leader of all devils of the Nine Hells. People know devils to be iron-minded and silver-tongued purveyors of temptation, whose price for their boons can be as dear as one's soul. It's said that when a soul waits on the Fugue Plane for a deity to take it to its appropriate afterlife, devils approach the soul and offer it a chance at power and immortal pleasures. All a soul needs to do is take one step out of the dust and the milling crowd and put a foot on the first rung of the infernal ladder that represents the hierarchy of the Nine Hells.
The faithful of Asmodeus acknowledge that devils offer their worshipers a path that's not for everyone—just as eternally basking in the light of Lathander or endlessly swinging a hammer in the mines of Moradin might not be for everyone. Those who serve Asmodeus in life hope to be summoned out of the moaning masses of the Fugue Plane after death. They yearn for the chance to master their own fates, with all of eternity to achieve their goals.
To those not so dedicated, priests of Asmodeus offer the prospect of a reprieve in the afterlife. All souls wait on the Fugue Plane for a deity's pleasure, which determines where a soul will spend the rest of eternity. Those who lived their lives most in keeping with a deity's outlook are taken first. Others, who have transgressed in the eyes of their favored god or have not followed any particular ethos, might wait centuries before Kelemvor judges where they go. People who fear such a fate can pray to Asmodeus, his priests say, and in return a devil will grant a waiting soul some comfort.
Today, shrines to Asmodeus are still rare and temples are almost unheard of, but many folk have adopted the habit of asking Asmodeus for reprieve from their sins. After transgressing against a god in some way, a person prays to Asmodeus for something to provide respite during the long wait. Asmodeus is known to grant people what they wish, and thus people pray for all the delights and distractions they desire most from life. Those who transgress in great ways often ask Asmodeus to hide their sins from the gods, and priests say that he will do so, but with a price after death.

Mordenkainen's Tome of Foes

Asmodeus is an unmatched strategist and orator. The most epic of all his achievements is chronicled in The Trial of Asmodeus, a play based on purportedly true events as researched by the aasimar bard Anodius.
In ancient times, as the Blood War raged, the angels of law and good that dwell on Mount Celestia issued a decree accusing Asmodeus of terrible crimes. Outraged by such claims, the Lord of the Nine Hells petitioned for the right to answer the charges before his accusers. The angels, although shocked at his impudence, accepted his petition and agreed to hear the bargain he proposed. Both sides, he suggested, would present their case to Primus, leader of the modrons. As a creature of absolute law, Primus could be trusted to issue a fair and impartial verdict. Asmodeus drafted a contract to seal the deal, and the angels-after carefully scrutinizing the terms-agreed to the trial.
When he testified before Primus, Asmodeus attributed his actions to the dictates of law and the survival of the cosmos. He admitted that he swayed mortals to evil, but he and his minions never breached a contract and explained the terms clearly. Had they not obeyed the rule of law in doing so? Was it not mortal ambition, rather than infernal deception, that led so many souls astray?
Asmodeus also pointed out that the souls harvested from the Material Plane went on to serve in the infernal legions that repel the endless tide of the Abyss. Were not such souls put to good use against the demonic hordes, a power that if unchecked would scour the universe of all lawfulness and goodness?
He further asserted that he was bound to the rules and traditions of the Nine Hells, compelled to adhere to law and to maintain the devils' trafficking in souls. If he violated those laws, he would be no better than the demons he fought. Mortals who refused a devil's offer were left alone, in accordance with the law. Those who struck deals with his followers and then somehow turned the contracts against the devils were freed from their debts. A contract is the law, and the law is a contract.
Primus weighed Asmodeus's words and listened patiently as angel after angel testified to his crimes. Hours turned to days and days into weeks as more and more of his sins entered the court record.
Even Primus's patience has its limits, and in time, the remaining angels who were eager to testify were told that only a few more would be allowed to speak. A brawl broke out when one angel, Zariel, pushed her way to the front and demanded to be heard. As the scuffle turned into a battle, Asmodeus looked on with a smirk.
In the end, Primus declined to issue a definitive judgment. He rebuked the angels for their descent into infighting, but didn't punish Asmodeus for his evil ways. He did, however, order Asmodeus to forever carry a mighty artifact, the Ruby Rod, that would guarantee his adherence to law. The artifact, which has remained at Asmodeus's side ever since, grants him and his underlings the right to enter into contracts with mortals for their souls but unleashes an inescapable punishment upon any devil that breaches such a contract.

He Who Would Rule

Asmodeus wants to rule the cosmos. Under his watch, he believes, the universe would take on a pristine, perfect state, with every living creature assigned a place in the infernal hierarchy. Wars would end, and every creature would have a purpose to fulfill. The universe would be a utopia, at least as Asmodeus views such a thing.
Of course, as he sees it, Asmodeus is the only being with the charisma, strength, and insight necessary to shepherd in this ideal future. His rivals are inferiors who, if left to their own devices, will turn the cosmos into a demon-infested maelstrom. The powers of good are sentimental fools, too delicate and soft to do what must be done. In his mind, Asmodeus has been chosen by the universe to protect it from annihilation.
If Asmodeus were any less capable, his arrogance would have led to his undoing long ago. Yet still he sits atop his throne, having thwarted every conspiracy mounted against him. He once walked into the lair of one of his enemies in Mount Celestia and survived using nothing more than his words and his wits. Even his most ardent enemies must grudgingly admit that his skill and competence are unparalleled.

Power without Limit

Unlike the other Lords of the Nine, Asmodeus has no quota of souls to fill. Any soul recruited by any denizen of the Nine Hells is also pledged in his name, and a cult dedicated to any other devil is also dedicated to him. Because he doesn't need to spend his time courting mortals, he concentrates on manipulating demigods and beings of similar station. Occasionally, he lures such a being into a contract and adds a new, unique devil to the ranks of the Hells. His most recent recruit is Zariel, a former angel. His supposed daughter, Glasya, is thought by some sages to be a godlike entity of unknown origin.

Lord of Nessus

Asmodeus resides in Nessus, the bottommost layer of the Nine Hells. By design, the place is devoid of activity, since Asmodeus values his privacy and safety. The environment is a rocky wasteland, crisscrossed by deep fissures and lacking roads, bridges, and other means of passage. Asmodeus dwells in a great fortress somewhere in the wasteland, at the bottom of its deepest pit. Only his most trusted followers and most important advisors know the route to it. He remains inside, relying on messengers and magic to convey his dictates.

Divine Classification

Greater Deity

Alignment

Lawful Evil