From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Old Kaioshin (老 界王神, Rō Kaiōshin; FUNimation "Old Kai", Viz "Former Kaioshin"; Literally meaning "Old World King God") is a Kaioshin.
Old Kaioshin's personality and demeanor are very perverted and self-centered, much like Muten Roshi's, but with the capability to make a sacrifice at the right time if the need arises, another similarity. He has a very perverted mind and loves dirty magazines (as a matter of fact, one of Goku's first bribes to him was loaning him some of Master Roshi's Girlie Magazines, much to Gohan and Supreme Kai's chagrin.). It's shown during the Majin Buu Saga when Goku bribed him of those to find out a power that he was boasting about, but says he can use his vision to see girls play beach volleyball (in the original manga, he simply states he can watch them strip if he needs to). He eventually accepts the offer to be able to kiss an Earth woman; in the original manga, it was porn of one, and in the Japanese version of the anime, it was to grope Bulma's breasts, much like Master Roshi wanted to multiple times throughout Dragon Ball and Dragon Ball Z. He is also somewhat childish at times as he throws a tantrum because he "can't see all the action" inside Majin Buu, while also reading comedy comics while powering up Gohan and stating that he can't think on an empty stomach. Despite these tendencies, he can be considered to be one of the wisest characters in the series as he has frequently displayed knowledge that no other Kai has shown, including the Potara fusion and the fact that Buu had followed Goten and Trunks into the Hyperbolic Time Chamber.
Old Kaioshin has the power to raise a being's ability to their maximum potential and beyond it. This was gained from fusing with the Old Witch. He often boasts and calls it his "menacing capacities". The ritual begins with him slowly pacing around the participant for five hours making brief shouts. During that time the participant has to stand patiently. Afterwards, they both sit facing each other for twenty hours, a process that may take longer should the participant's potential be that much higher. During this time the participant must be still, but Old Kaioshin was able to do things such as read, which further frustrated Gohan. He also has other powers like the ability to create objects out of nothing, a power common in the series, and the ability to view things in any world at any time (although for some reason, he was entirely unaware of the Dragon Balls' existence on Earth though he knew all about Majin Boo's reign of terror on the planet).
Old Kaioshin held the title of "East Kaioshin" 15 generations prior to the current East Kaioshin. Long before the events of the series, Old Kaioshin was once a youthful and handsome looking being (though still knows about the abilities of the Potara Earrings because of his horrified expression when it was taken) until one day the Old Witch snuck up on him while he was reading a comic book and took one of the Potara Earrings that he was wearing. She put the earring on her ear which caused the two to fuse. This caused him to become an old wrinkly being with a personality befitting of the new form, as well as new magical powers. Some time after this Potara Earrings Fusion, Old Kaioshin was sealed by an enemy. According to him, this enemy was very powerful, but not as powerful as Majin Boo. He was sealed inside the Z Sword due to the enemy fearing his ability to raise a person's power gained from fusing with the witch.
During the Majin Buu Saga, East Kaioshin and Kibito were looking for warriors they believed would be strong enough to defeat Majin Boo. 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, Supreme Kai generated the strongest metal in the universe, katcheen, and gave it to Goku to throw. When Gohan hit the metal, the Z Sword broke in half, releasing Old Kaioshin.
Old Kaioshin 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 Kaioshin had finally unleashed Gohan's hidden potential. After Gohan lost to Super Buu, Old Kaioshin revealed the method of Potara Earrings Fusion to Goku and gave him the Potara Earrings to fuse with Gohan, sacrificing his life so that he may return to Earth (though Goku would end up fusing with Vegeta, creating Vegito). He then gives up his life so Goku can live again and return to Earth to fuse with Gohan to defeat Buu. When Kid Boo had been brought out, he 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 Boo. Old Kai was brought back to life by the wish made to Polunga to revive everyone who died after the World Tournament, and so his halo disappeared after the wish was made.
In Dragon Ball GT, Old Kaioshin played a prominent part towards the middle of the Baby Saga by helping Goku's tail grow back to help him fight Baby, which allows Goku to ascend and transform into Super Saiyan 4. For some reason, he knew about the SS4 form, indicating that there were SS4s before Goku. It may have been the Original Super Saiyan. During the Shadow Dragon Saga, he and Kibito Kai explained to the Z Warriors how the Shadow Dragons were born from the Negative Energy that was stored in the Dragon Balls, after years of overusing the balls to grant wishes. As the Dragon Ball GT series comes to a close, both he and Kibito Kai watched Goku defeat all of the Evil Dragons and restore the natural order of the universe.
Before the Evil Dragons are born, Old Kaioshin gives an ultimatum to Goku that the Dragon Balls they are using are very dangerous and have the potential to destroy the whole universe. Since he does not provide an explanation, Goku and others assume that he is simply being prudish, and proceed to use the balls without heeding his warning. Later, with the birth of the Evil Dragons, especially Syn Shen Long, the Z Warriors are able to understand what Old Kaioshin had feared.
- Japanese dub: Reizō Nomoto, Isamu Tanonaka (Dragonball Z: Budokai Tenkaichi 3)
- Ocean Group dub: Scott McNeil
- FUNimation dub: Kent Williams
- Old Kaioshin is sometimes referred to as Elder Kai in the anime.
- Despite being dead, Old Kaioshin is able to leave the Next World and travel to the physical world without the help of Uranai Baba. It is possible that his prestigious position in the universe allowed certain privileges to make this possible, or it could be the witch he fused with having the same powers as Baba.
- There is a scene where the Crystal Ball malfunctions and Old Kaioshin says, "They don't make Crystal Balls like they used to." Kibit-Kaioshin says, "But I made that one myself!" Old Kaioshin is the one who made the Crystal Ball, not Kibit-Kaioshin/East Kaioshin.
- When powering up Gohan, Old Kaioshin reads a comic book. At times, he is shown flipping the pages backwards, implying that like manga, this comic starts on the last page and goes backwards. At other times, however, he is shown flipping the pages forwards. This could be explained by the comic having panels which hold his perverse attention, giving him the desire to turn back to them occasionally.
- Old Kaioshin's wisdom has assisted in the creation of three of the series' most powerful transformations by the good side: Ultimate Gohan, Vegetto, and Super Saiyan 4 Goku.
- Before merging with the Old Witch, Old Kaioshin looks nearly identical to East Kaioshin, except that his skin and hair are violet rather than purple.
- Old Kaioshin knew of the Super Saiyan 4 transformation and even called it by name after Goku transformed, yet he did not seem to know why Goku's battle power did not increase at all before transforming. During the Kid Boo Saga, he does not suggest the transformation as a means to beat Boo. This can be explained by Dragon Ball GT being anime-only. When Akira Toriyama first created Dragon Ball, he did not know that Dragon Ball GT would even exist.
- Old Kaioshin states in "Super Moves of Gotenks" that he has trouble digesting Mexican food. Like the countries mentioned in Dragon Ball Z: Super Android 13!, it does not exist in the Dragon World.
- He is the second Kaio/Kaioshin to experience death during the series after North Kaio (at least on-screen because the other Kaioshins were killed off by Boo long before).
- He is the oldest known character in the series. According to the timeline, he is over 75 million years old.
- Old Kaioshin and Turtle Hermit have a bit in common. They are both incredibly old (even for the Kaioshin's race), extremely perverted, and have great wisdom for their students. Goku even notes the similarity once when he makes a deal with Old Kaioshin to have him unlock his son's full potential.
- Old Kaioshin can be heard listening to the original FUNimation Dragon Ball GT opening theme song (dub only) during the Shadow Dragons Saga.
- The ritual dance he performs when unlocking Gohan's hidden power is very similar to Dracula Man's dance when fighting against Kuririn.