In the film *Mazinger Z vs. Devilman*, Dr. Hell commands attention as the primary antagonist, an elderly figure with striking purple skin, intense yellow eyes, and flowing white hair and beard. He wears a green jumpsuit, black gloves, and a regal cape. His dark history began as a WWII medic where he met Count Broken, later transforming him into a cyborg. Joining Juzo Kabuto’s Bardos Island expedition, Dr. Hell uncovered ancient Mechanical Beasts, then betrayed and slaughtered the scientists—sparing only Kabuto—to seize the Beasts for his world conquest.

During the film, Dr. Hell observes Mazinger Z and Aphrodite A battling his Mechanical Beasts, accidentally freeing the demon Sirene. Identifying her as part of the prehistoric Demon Tribe, he pursues Sirene to the Himalayas aboard his fortress Navalon, flanked by Baron Ashura. There, he awakens Sirene, the amorphous Bugo, and leader Zannin from icy imprisonment, embedding mind-control microchips in their chests. He negotiates an alliance: demons aid him against Mazinger Z in exchange for his support against Devilman.

Strategically cunning, Dr. Hell deploys Sirene and Bugo to sabotage the Photon Power Laboratory’s Jet Scrander project. After partial success and hostage-taking by Sirene, he escalates with a combined demon-Mechanical Beast assault on the lab. Under his oversight, demons capture and torture Devilman during the attack. Dr. Hell thrives on opportunism and fragile alliances, yet Mazinger Z and Devilman repel his forces. When Navalon collapses in the climax, he escapes unharmed via a life pod retrieved by Ashura, vowing vengeance on Koji Kabuto and Mazinger Z.

Driven by megalomania, he relentlessly pursues global domination through technological might and exploitation of ancient forces. His manipulation of both organic demons and mechanical beasts cements his role as a coldly adaptable, calculating foe.