The devil that plans to take over Saddrac World. He was killed by Knight Gundam, who had attained the power of the stone tablet and the three sacred instruments, using the Sword of Flame. His body fell into a volcano, but his soul took over Warrior Guncannon. After taking Guncannon to the Mua world, the home base of the Zeon Clan, his soul fused with Dragon Baby and the Sword of Flame to be resurrected as Neo Black Dragon. During his decisive battle with Vassal Knight Gundam, it is revealed that Satan Gundam had been used as a pawn of Dark Emperor Sieg Zeon to prevent the revival of Superior Dragon by killing Knight Gundam. Just then, an arc of light connects Satan Gundam to Knight Gundam, and the two of them realize that they were originally the same person. Accepting this, they fuse into Superior Dragon.
Originally, he was the evil half of Musha Gundam Mark Three. When Musha Mark Three was summoned to the Saddrac World as the new core unit of Superior Dragon, he was split into a good and evil half by Sieg Zeon himself. His evil half then fused with a dragon upon landing in the Saddrac World, creating Satan Gundam. In other words, Superior Dragon is Musha Mark Three fused with a dragon.