He/she is a hideous humanoid monster. Long ago, a man and a woman fell in love but were killed. The man's left half and the woman's right half were sewn in by Dr. Hell, thus creating the humanoid Baron Ashura.
At the start of the Mazinger Z series, he/she murders Koji Kabuto's father while he was working on a new type of robot called Mazinger Z.
Since Kabuto's first Mazinger piloting, Baron Ashura has tried several attempts to put a stop to the heroic robot. All of them have mostly ended in failure and have left him/her scolded by Dr. Hell. They had a submarine called Bood that could pull ships down into the ocean and sink it. In addition, they had two rivals, Archduke Goron and the headless Count Brocken.
In the big battle with Mazinger, Baron Ashura tries to ram his/her sub into the robot, but they fail and he/she was killed. The baron then dies in Gorgon's arms.