Dagra Dai was once a human philosopher, but this changed when he came across the battle of the Greater Fiends. When Vazdah awoke, he looked into the eyes of the Archfiend, driving him mad and granting him great powers as a fiend, causing a third eye to appear on his forehead. Dagra Dai became the Infernal High Priest and leader of the Necromantale, a group of fiends that worshipped Vazdah as a god. Millennia later, after the Archfiend and his Greater Fiends were defeated and sealed by the ninjas of the Dragon Lineage, he began planning for the Archfiend's resurrection and awakened the Greater Fiend, Elizébet, commanding her to retrieve a special demon statue in possession of the Dragon Lineage, then awaken the other Greater Fiends, since when the statue had been enchanted by the power of their hearts, it could open a gate in the Underworld to the sealed Vazdah. Upon Elizébet's success, Dagra Dai opened a portal in Mt. Fuji that linked the fiend world with Earth, that he descended into. He began performing a blood sacrifice ritual that brought back Vazdah in his larval form and continued the ritual so as to return the Archfiend to his true form. However Ryu Hayabusa managed to interrupt the ritual and Dagra Dai attacked him, transforming into his fiend form. But the Dragon Ninja managed to defeat him and in one last desperate effort to restore Vazdah's powers to their prime, he offered his flesh and blood to his lord. Dagra Dai hoped this would bring him back to his full power and the Archfiend accepted, tearing apart the Inferno High Priest's body.
Dagra Dai is quite powerful with strength comparable to that of a Greater Fiend and wields a pair of swords in combat. He can summon fiends to his side, generate blasts of energy resembling electricity from his swords that can either be continuous or rapid fire, use a quartet of tentacles on his back to move around and lash out at his enemies, teleport, and levitate. Dagra Dai also possesses knowledge in the field of fiend rituals.