Heirs of Waterdeep
Asmodeus was depicted as the strongest, most cunning, and most beautiful of all devils. He was typically described as appearing as a human, 13 feet tall, he has lustrous dark skin and black hair, handsome and dangerous, his crimson eyes shown with infernal power, a pair of small sharp horns crowned his forehead. He dressed in regal finery of red and black robes studded with black diamonds and fiery rubies, which were of unimaginable expense.
Beneath his clothing, Asmodeus’s body was covered in bloody wounds which he sustained when he fell from heaven. His wounds oozed blood daily, and the drops of his blood which touched the ground grew into powerful devils and demons.
Asmodeus was never seen without his Ruby Rod of Asmodeus, seemingly made of a single carved ruby that shone with the power of Hell, that served as a badge of office as well as having several powerful offensive and defensive powers. The Rod allowed Asmodeus to attack with elemental forces, force his enemies to cower in fear, or cover himself with a field which healed and protected him.
Asmodeus, an archdevil before the Spellplague, Supreme of the Nine Hells (or Baator), was the god of sin. An ever ambitious and careful creature, Asmodeus retained his position all through the Reckoning of Hell, unlike many of the other archdevils. Asmodeus was lord of Nessus, the Ninth Layer of Hell, though he was generally recognized as lord of all of his divine dominion of Baator, which lay within the Astral Sea.
When Dweomerheart collapsed in the wake of Mystra’s death, her servant Azuth fell into the Hells where Asmodeus, sensing his opportunity, devoured the lesser deity and became a god himself. He then ended the Blood War by forcing the Abyss underneath the Elemental Chaos. Malgoth tried to save Azuth but was too late and unable to battle Asmodeus on his home plane.
Asmodeus was the undisputed master of the Nine Hells, commanding fear and respect from all those who occupied his realm. Even the gods who dwelt in the Nine Hells gave Asmodeus his proper due. Though the archdevils might work to usurp him, few had the courage to act openly. Asmodeus’s machinations were long in the making, and they might take centuries, if not millennia, to see resolution.
He worked on a grand scale, carefully constructing insidious and inexplicable intrigues, maneuvering the forces of wickedness like chess pieces on a board that encompasses all the planes. His core concerns were simple. First, he wanted the power structure currently in place to remain exactly as it stood, with him in charge. He had spies on every layer, plants in every court. No fiend knew for sure which of its minions actually served Asmodeus, so the climate was one of justified paranoia. Asmodeus also expanded evil. He directly opposed celestials and good-aligned deities. His minions combated the agents of the Celestial Planes, murdering them whenever and wherever they could.
Finally, Asmodeus waged war against the demons throughout the period of the Blood War. He saw the untold legions as a direct threat to his supremacy. Asmodeus was aware of every plot hatched against him. Older than the oldest archdevil, he watched the rise and fall of other archdevils far craftier than any of Asmodeus’s contemporaries. He kept to himself, letting his minions stew in fear of what he would do next. Of course, few forgot that Asmodeus emerged unscathed in the Reckoning, proving to all that he was their better. On the Prime Material Plane, Asmodeus had more cultists than all the other archdevils combined. Mortals who worshiped devils actually drew power from Asmodeus.
He influenced all levels of society and had followers of nearly every race, even within the strongest bastions for good. His path was the way to great and unattainable power, so his clerics were mighty men and women with influence and personal magnetism that made them natural leaders among their kind.