Dr. Hell was an elderly man with long white hair and a beard, he had purple skin with yellow eyes. He wore a green jumpsuit, black gloves and a long flowing cape.
In the crossover film Mazinger Z VS. Devilman he is responsible for the battle between Aphrodite A, Mazinger Z, Zaurus F1, Demonger J5 and Buragga S1 which released the famous demoness Sirene. He showed to know who Sirene was and had knowledge of the Demon race. He followed Sirene to the Himalayas were her fellow demons in hibernation. Dr. Hell sent a Mechanical Beast named Mantes K9 and used its drills to release several demons out of them Dr. Hell places mind controling microchips into the minds of Sirene, an amorphous demon Bugo and the tribes leader Zannin.
Later when Devilman and Mazinger Z had defeated the demons and a large group of Mechanical Beasts, they focus on Dr. Hell's flying fortress the Navalon and destroy its engine causing it to sink into the ocean, Dr. Hell however expected this and escaped in a life pod were he was picked up by Baron Ashura in the Bood, shaken but not badly wounded Dr.Hell swears revenge against Koji Kabuto and the Mazinger Z.