Baron Ashura began as two separate individuals engaged in a forbidden romance. Discovered and condemned to live mummification, they were entombed together. A cave-in later destroyed the male's right half and the female's left half. Dr. Hell unearthed these remains on Bardos Island and surgically fused the viable halves into a single cyborg entity, naming it Baron Ashura. In some versions, these individuals were named Tristan and Isolde, ancient Mycenaean priests who conspired against Zeus before their entombment.

This composite being displays a stark physical duality: the left half exhibits masculine traits with darker skin, more body hair, a thicker eyebrow, and a blackened eye, while the right half shows feminine features with lighter skin, green eyeliner, and red lipstick. Baron Ashura typically wears a robe split purple on the male side and black on the female side, often concealing the head with a hood.

Personality is defined by unwavering loyalty to Dr. Hell, fueled by gratitude for resurrection and fear of disapproval. This loyalty sometimes drove extreme actions, including choosing death over failure. A persistent rivalry with fellow lieutenant Count Brocken involved sabotage attempts to retain favor. Baron Ashura demonstrated strategic competence commanding Mechanical Beasts and the Ashura Corps, though overconfidence frequently led to defeat by Mazinger Z. Additional traits included arrogance, cruelty towards civilians, and mastery of disguise for infiltration or manipulation.

Primary abilities centered on the Bardos Wand, enabling control of Mechanical Beasts and occasional human brainwashing. As commander, Baron Ashura directed the Ashura Corps and orchestrated large-scale attacks using Dr. Hell's forces. Physical capabilities included superhuman strength, evidenced by briefly overpowering Mazinger Z, and agility, such as sprinting across water. One continuity featured implanted brainwashing by Tsubasa Nishikiori and Dr. Hell, preventing attacks against them or allies until Dr. Hell's death negated the programming.

Baron Ashura served as Dr. Hell's primary lieutenant early on, assassinating Professor Juzo Kabuto with a bomb and initiating assaults on the Photon Power Laboratory. Repeated failures against Mazinger Z eroded Dr. Hell's trust, leading to Count Brocken's introduction as a rival. Operations included commanding the submarine fortresses Saluud and later Bood, overseeing attacks on Japanese cities, and retrieving assets like the Danube α1 Mechanical Beast. In the original continuity, Baron Ashura perished in a suicidal ramming attack against Mazinger Z using the Bood, receiving posthumous recognition from Archduke Gorgon. An alternate conclusion involved self-sacrifice through bodily separation to awaken the Mycenae Empire after realizing Dr. Hell opposed its restoration.