From the dragonball series, during the Buu sagas, it is revealed that Grand Supreme Kai (Dai Kaioshin) was the ruler of the entire universe before being absorbed by Majin Buu. By being absorbed, the Kais good influence weakened Buu rather than strengthening him, as he turned into a childish form, as Goku described it, he was like "A naughty child who didn't know any better".
He gave his life for the East Supreme Kai, who would be later known as simply Supreme Kai, as there were no other supreme Kais after Buu's assault on the Kai planet. Although the title of Grand Supreme Kai was never actually given to West Supreme Kai, due to the other Supreme Kais deaths, he assumed Grand Supreme Kais' job of overseeing the entire universe, and was henceforth referred to only as THE Supreme Kai.
He gave his life for the East Supreme Kai, who would be later known as simply Supreme Kai, as there were no other supreme Kais after Buu's assault on the Kai planet. Although the title of Grand Supreme Kai was never actually given to West Supreme Kai, due to the other Supreme Kais deaths, he assumed Grand Supreme Kais' job of overseeing the entire universe, and was henceforth referred to only as THE Supreme Kai.
Grand Supreme Kai (大界王神, Dai Kaiôshin), or Daikaioh, was the highest of all Supreme Kais and ruled over the entire universe. He is only seen in (Eastern) Supreme Kai's flashback. He lived on the Sacred World of the Kais in Other World, along with the four other Supreme Kais.
by kyle.biddle January 20, 2011