Daraomu is a central antagonist in the story, serving as the leader of the three High Priests of the dark organization Gorgom. As the High Priest, he answers only to the Creation King, the supreme ruler of the organization, and is depicted as a small, elderly man with a pale, white face, standing at 153 centimeters tall. Despite his unassuming physical stature, Daraomu possesses a brilliant and calculating mind, making him the most strategic and often the most dangerous of the three priests.

In terms of personality, Daraomu is characterized by his cold, ruthless intelligence and his deep-seated hatred for his enemies, especially Kamen Rider BLACK. He is cunning and manipulative, preferring to use his psychic abilities and intellect to achieve Gorgom's goals from the shadows, though he is not afraid to engage in direct combat when necessary. While he often acts as the voice of reason within the trio, intervening in petty squabbles between his fellow priests Baraom and Bilgenia, he is fundamentally an elitist who holds a low opinion of lesser monsters, which he famously demonstrates during the final stages of the series. His primary motivation is unwavering loyalty to Gorgom and the completion of its ultimate objective: the resurrection of the Creation King and the subjugation of humanity.

Daraomu plays a critical role as a recurring antagonist throughout the story. As a High Priest, he is directly responsible for overseeing many of Gorgom's operations, including the genetic modification of humans into mutants. He has the ability to fire a genetic manipulation beam from his right hand, which he uses to alter humans or put monsters to sleep. His key relationships include his rivalry with the hero, Kotaro Minami, the titular Kamen Rider BLACK, and his service to Shadow Moon, the reborn Creation King. After the other two High Priests, Baraom and Bishum, are defeated, Daraom becomes the final priest and takes a more active, frontline role in the conflict.

Daraom undergoes a significant transformation towards the climax of the series. After expending the energy of his blue "Stone of Heaven" to facilitate the birth of Shadow Moon, he evolves into a more powerful form known as Grand Mutant Daraom. In this new state, he resembles a trilobite, gaining enhanced physical abilities, retractable antennae that can be used like whips, and the power to teleport. His combat skills are magnified, allowing him to fight Kamen Rider BLACK on equal terms, often in coordination with his fellow Grand Mutants. This transformation also appears to affect his personality, as his contempt for lower-ranking monsters becomes more pronounced.

As Grand Mutant Daraom, his notable abilities become even more formidable. He possesses powerful psychokinesis, which he can use to manipulate objects and attack his foes. He can discharge powerful destructive beams from his fingertips and from the antennae on his head. These antennae are also fully prehensile and can extend at will to strike or bind an opponent like a whip. He has superhuman speed and reflexes, described as being able to react at the speed of light, and his attack potency is rated as being able to cause large-island level damage. Ultimately, after a fierce battle, he is defeated by Kamen Rider BLACK, who uses a combination of the Rider Punch and Rider Kick to destroy him.