From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Dragon Ball Z
Kid Buu Saga
Kibito Kai was first born when Old Kaioshin explained the Potara Earrings Fusion. The Supreme Kai and Kibito, thinking nothing of testing out the earrings, fused into Kibito Kai. He was apparently pleased with his appearance until Old Kaioshin revealed that the transformation was irreversible. When Kid Buu prepared to blow up Earth, Kibito Kai teleported to Earth and rescued Son Goku, Vegeta, Hercule, and Dende just before the explosion and brought them to Kai Planet. With Kid Buu tracked the Saiyans to Sacred World of the Kais, Kibito Kai, Old Kaioshin, and Dende teleported to a faraway planet and watched the ensuing battle on a Crystal Ball.
After the evil half of Majin Boo was vanquished, Kibito Kai, Old Kaishin, and Dende teleported back to Sacred World of the Kais and healed the warriors, including the good, Fat Majin Buu who had reformed earlier on and been excluded from Kid Buu's body.
Kibito Kai teleported Goku, Vegeta, Hercule, Dende, and Fat Boo to Earth and bid them farewell, teleporting himself back to Sacred World of the Kais where he would now rest in peace.
His personality is for the most part identical to the Supreme Kai's, except the unusual amount of concern he had for the damage the fight with Buu was doing to his planet.
Dragon Ball GT
Twenty years later, Kibito Kai would once again be forced into action while the Tuffle parasite, Baby, was terrorizing the Earth and completely dominating the now-child Goku in battle. Knowing of a secret Saiyan Technique, Kibito Kai and Old Kai saved Goku at the last minute and brought him to the Sacred World of the Kais, where he would undergo a painful procedure in which he would regrow his Saiyan tail via a giant pair of pliers.
Eventually, Goku's tail grew back, and he was able to use the secret technique by turning into a Golden Great Ape, which would turn into a Super Saiyan 4 once controlled. Meanwhile, Kibito Kai traveled to Kami's Lookout to get the pure water to cleanse the human race of Baby's parasites. With Baby no match whatsoever for a Super Saiyan 4, Goku would use this new power to destroy the Tuffle Parasite by blasting him into the core of the Sun.
Watching from the Sacred World of the Kais, Kibito Kai and Old Kai were two of the many people to celebrate Baby's defeat, although Old Kai expressed his disgust at the use of the Dragon Balls once again, for he knew something about the mystical artifacts that Goku and his friends did not. This prediction, soon lead to the birth of the Shadow Dragons, born from the negative energy that was stored inside the Dragon Balls, due to the overuseage of using the balls.
Shadow Dragon Saga
It was after when the Black Smoke Shenron, separated into the 7 other Evil Dragons, and scattered across various corners of the Earth, that Kibito Kai and Old Kai, explained to Goku and the others, of how overusing the Dragon Balls, lead to the birth of the 7 Shadow Dragons. Both Kibito Kai and Old Kai, merely watches as Goku defeats all the 7 Evil Dragons, and restores the natural order of balance, back to the universe.
Kibito Kai has appeared as a playable character in the video games Dragon Ball Z: Super Butōden 3, Dragon Ball Z: Budokai 2, and Dragon Ball Z: Budokai 3. In all three games, he appears as a single fighter, although a Potara Earring Fusion can be unlocked if the player accomplishes certain tasks. He also appears as a playable character as Kibito Kai in Dragon Ball Z: Budokai Tenkaichi 2 and its sequel. He also appears in the game Dragon Ball Z: Buu's Fury and Dragon Ball GT: Transformation.
- Instantaneous Movement – A technique that allows its user to instantly teleport to another planet, place or person. Unlike Instant Transmission, the user does not actually need to focus on a specific energy signature to use as a target, as well as the technique is not limited by distance. Goku uses instant transmission which was learnt after the Frieza Saga from the Yardrats.