Edward Bilstein, also simply called Bilstein, is the main villain of Star Gladiator and it's sequel Plasma Sword: Nightmare of Bilstein.
Doctor Edward Bilstein was a world renowned physicist and Nobel-prize winner who worked for the Earth Federation. One day, after discovering secret documents left by his ancestors, Bilstein uncovered a new form of energy which he dubbed "Plasma Power": it allowed to channel one person's mental power into a variety of weapons. Bilstein earned fame and fortune from his discovery, but it was soon discovered that Bilstein had performed his tests on innocent people, and because of this he is imprisoned on a satellite prison orbiting Planet Zeta.
Four years later, Bilstein escapes the prison, having built a new mechanical body for himself and creating a rebel group called the Fourth Empire, which takes over Zeta and starts conquering all nearby planets. Knowing it would only be a matter of time before Bilstein reached Earth, the Earth Federation creates the Star Gladiator project to find people capable of wielding Plasma Power, sending the chosen individuals to stop Bilstein at all costs.
He was, however, not alone, as he had called upon his loyal subordinates and his precious american-german daughter, Catherine Rain Bilstein
The epic battle between the Star Gladiators and the Fourth Empire would become known as the "Final Crusade". During this battle, Bilstein was finally killed by Hayato Kanzaki, one of the Star Gladiators. However, his soul was able to transcend death, reincarnating in a new robotic body a year later. Bilstein once again gathers his forces, resuming his plans for conquest. His forces once again clash with the Star Gladiators, but he is once again killed by Hayato, this time for good.