地球聯邦
Four years later, an Earth Federation army base is attacked and destroyed by a small group of rebels calling themselves the "Fourth Empire". Bilstein, who has built himself a powerful cyborg body and escaped from Zeta, is their leader. Realizing their pattern of attacks is leading back to Earth, a panicked Earth Federation searches for people who can utilize Plasma Power in their own given accord and stop Bilstein before he can conquer the universe with his nascent Fourth Empire. All of Earth's hopes rest in the project codenamed "Star Gladiator".