Elder Kai's History
Background
One day, an Old Witch snuck up on the Former Supreme Kai while he was reading a comic book and took one of the Potara Earrings that he was wearing, leaving the Supreme Kai with a horrified expression as he knows about the abilities of the Potara Earrings. She put the earring on her ear which caused the two to fuse. This caused them to fuse into an old wrinkly being with a personality befitting of the new form, as well as new magical powers. In the past, Old Kai visited Zeno three times. Once every 1,000 years, the Supreme Kais and the Gods of Destruction go to each other's realms and hold a coordination meeting. During one of these meetings, held roughly 75 Million Before Age, they got into an argument over some trifling thing and a certain short-tempered Beerus sealed Old Kai away inside the Z Sword as it would not have been proper for him to destroy the Sacred World of the Kai itself.[4] According to Old Kai, the person who sealed him inside the sword was very powerful but not as bad as Majin Buu.
Majin Buu Saga
Shin and Kibito were looking for warriors they believed would be strong enough to defeat Majin Buu. They eventually ended up with Gohan and had him remove the Z-Sword from its stone encasement. Goku eventually showed up and started to help Gohan train. To test the blade, Shin generated a cube of the strongest metal in the universe, Katchin, and gave it to Goku to throw. When Gohan hit the metal, the Z-Sword broke in half, releasing Old Kai. After Old Kai expressed disappointment in Shin and Kibito for not breaking the sword's seal yet Gohan, a mortal, was able to break it, Goku tried to test Old Kai's power level by throwing a basic Ki Blast at him, with little enough power to deflect, and it instead knocked Old Kai down, resulting in Old Kai scolding Goku, although after both Goku and Gohan explained what Goku's intention behind it, he then elaborated that what made him threatening was not his raw strength, but rather his smarts, or more specifically, drawing people's latent abilities out.
Old Kai told them that he could bring out Gohan's latent abilities by doing an "essential ritual". After waiting for well over an entire day, Old Kai had finally unleashed Gohan's hidden potential. After Gohan lost to Super Buu, Old Kai revealed the method of Potara Fusion to Goku and gave him the Potara Earrings to fuse with Gohan, (though Goku would end up fusing with Vegeta, creating Vegito).
He then gives up his life to Goku so he can return to Earth to fuse with Gohan and defeat Buu. When they decided to use the Namekian Dragon Balls to restore Earth and revive everyone, Old Kai refused to use them, as he claims that they would disrupt the balance of nature. However, he went along with it when Goku reminded him of his deal regarding his groping/gaining nude pictures of a human woman, with Goku inadvertently admitting in front of Vegeta that the woman in question was Bulma. When Super Buu reverted to Kid Buu, Old Kai went to Namek with Dende and Kibito Kai, where he and the others used the Namekian Dragon Balls to help Goku and Vegeta defeat Kid Buu. Old Kai was brought back to life by the wish made to Porunga to revive everyone who died after the 25th World Martial Arts Tournament, and so his halo disappeared after the wish was made.
God of Destruction Beerus Saga
Sometime after Kid Buu's death, Old Kai and Kibito Kai notice a planet's disappeared and wonder what's to come of the universe. While the two were having tea, Old Kai senses that another planet has disappeared and tells Kibito Kai that the God of Destruction Beerus has been awoken and that the universe is in serious trouble.
The following day, he along with Kibito Kai watch the titanic battle that goes on between the newly Super Saiyan God Goku and Beerus. As their battle picks up the two begin exchanging blows that create shock waves. Old Kai explains to Kibito Kai that these shock waves are like a tidal wave after an earthquake and gradually get stronger the further out that they travel. He estimates that as many as three of these shock waves would cause all the planets, stars, realms and even Goku and Beerus would be enough to wipe everything out. Later when faced with imminent death, Old Kai offers Kibito Kai a Dirty magazine as a farewell gift though he throws it away disgusted.
Golden Frieza Saga
After the fight with Goku and Beerus, Old Kai and Kibito Kai are wondering about the recent mysterious disappearance of some planets, as if they disappeared by magic. When Old Kai suddenly gets distracted, Kibito Kai assumes he is using his divine sight to peep on women or something equally perverted, but he turns out to instead be watching two horned beetles wrestle.
Universe 6 Saga
Old Kai attends the tournament on the Nameless Planet with Shin and Kibito to spectate the battles between the members of Beerus' and Champa's teams. When Fuwa wonders if Old Kai knows Goku, Old Kai says it's a long story. Old Kai is a bystander and so he sits with the other gods. The first match is between Goku and Universe 6's fighter Botamo. While Goku is fighting Botamo, the Universe 6 Supreme Kai thinks that Botamo has the advantage over Goku but Old Kai doesn't think so.
Universe Survival Saga
Old Kai, alongside Shin, Kibito, Beerus, and Whis attend the Zeno Expo. During the 40 hour preparation for the Tournament of Power, Old Kai is eating alongside Beerus and Whis. During the Tournament of Power, he is happy when Universe 7's fighters eliminate opponents. He doesn't seem bothered by the fact that Krillin was knocked out of the arena because he let his guard down, probably since he thinks that Krillin's elimination isn't that big of a loss for Team Universe 7.
