Atollah is a demon of the Six Knights of Black within the Demon Clan. His humanoid form is asymmetrical: the left half is white with prominent cracking patterns across the face, torso, and arm, while the right side is a larger red mass extending over part of his face, obscuring his hourglass-shaped demonic mark.

He exhibits minimal emotion, driven primarily by a willingness to sacrifice souls to awaken an Indura. His history stretches back 3,000 years to the ancient Holy War, where he fought with the Six Knights against the Goddess Clan and others. During a crucial battle at the Sky Temple, the Knights unleashed an Indura, causing massive destruction. Following the Demon Clan's near-victory, the Great Oshiro intervened, defeated the Indura, and enabled the Goddess Clan to seal Atollah and his comrades within the Egg Rock.

Freed when the Egg Rock's seal breaks during the Sky Temple conflict, Atollah launches into capturing the souls of deceased Celestials to fuel a ritual releasing the sealed Indura. Celestial soldiers attempting to stop him fall prey to his nerve-controlling black seals, paralyzing them and allowing him to manipulate their movements against their will. In combat, he blocks attacks from King and Gowther using his body and traps them with his sealing magic. Gowther's lack of nerves renders the seals ineffective, enabling Gowther to trap Atollah in an illusion. King then petrifies him with Spirit Spear Chastiefol's Fossilization technique, and Gowther shatters his body, releasing all captured souls. His soul is later offered by Bellion as a sacrifice to awaken the Indura.

His combat abilities utilize his unique physiology; the red mass serves defensive functions, enables self-transportation, and traps enemies. His primary offensive tool is the nerve-manipulating seals, paralyzing targets and forcibly controlling their actions.