The Demon King Gokuaku (ゴクアーク Gokuāku?) is the ruler of the Great Demon World. He was sealed by Eldran for ages, but when the seal was broken, he immediately moved to conquer Earth and tried to change it into his domain. Gokuaku also has two brothers, Retsuaku and Saiaku, which are sealed in Egypt and Brazil respectively. This revival was cut short however when Eldran, sensing this, returned to re-seal Gokuaku and reverse the damage he did. While this succeeded, Gokuaku was able to send out one of his servants, Yaminorius III, through a small crack in his seal, to prepare the Earth for his takeover.
At the end of the series, he combines with his brothers to form his ultimate form, yet he is still defeated by the Ganba Team.