Dainichi Nyorai is the primordial creator deity within his Buddhist cosmology, embodying the universe itself and serving as the progenitor of all existence. As the central figure of the Five Dhyani Buddhas, he governs fundamental cosmic principles.

His personality manifests extreme narcissism and flamboyance. He frequently calls himself the "superstar of the great big universe" and employs grandiose, hammy declarations. This self-obsession is reflected in dramatic speech patterns, the use of the arrogant pronoun "ore-sama," and attire featuring galaxy motifs or clothing boldly emblazoned with "UNIVERSE" to underscore his cosmic identity. Despite this, he remains a capable leader and combatant.

His power critically depends on his halo, a tangible object that can be physically detached. Without it, he becomes entirely powerless, making the halo both a divine symbol and a tangible vulnerability. His relationship with his incarnation, Fudou Myouou, is tense; Fudou perceives unsettling changes in Dainichi's behavior, causing unease about his stability and motivations.

Within the anime adaptation, a lookalike named DJ Hotoke appears, creating confusion among other Buddhas during their search for Dainichi. As a key figure in the Thirteen Buddhas (Jūsanbutsu) group, he leverages his cosmic awareness to confront threats like the demon Māra and guide or influence events.