Docteur Inferno is an elderly antagonist with striking purple skin, long white hair, a white beard, and piercing yellow eyes, clad in a green jumpsuit, black gloves, and a dramatic flowing cape. Once a World War II medic, he betrayed his comrades during an expedition to Bardos Island, seizing control of ancient Mechanical Beasts to fuel his ambition for global domination. In *Mazinger Z vs. Devilman*, he allied with the Demon Tribe, reviving cryogenically frozen demons in the Himalayas and embedding mind-control transceivers in their chests to bend them to his will.

Commanding the aerial fortress Navalon and deploying Mechanical Beasts such as Mantes K9, he executed precise strikes against adversaries like Mazinger Z and Devilman. He weaponized the demons’ enmity toward Devilman—a renegade of their tribe—to destabilize both opposing factions. His strategies included disrupting the Jet Scrander’s development, a critical flight upgrade for Mazinger Z, and abducting allies to tilt battles in his favor.

Following Navalon’s destruction and the demons’ defeat, he fled via a life pod, swearing vengeance. His enduring traits span ruthless intellect, mastery of advanced technology, and manipulation of supernatural forces to cement his power.