Supreme Kai and Kibito fused using the Kai Earrings. Can now Kibito Kai use the earrings again to fuse with another?
I searched for this and found no creditable source.
I know for a fact that the ear rings still work, since they were offered by Kibito Kai to Goku and Vegeta before the battle against Kid Buu. However they destroyed it. So could Kibito Kai use it to fuse again?
Edit: Accepted answer has added a somewhat relevant frame. It doesn't make it explicit but seems to indicate that fused individuals such as Elder kai, Kibito Kai and Vegeto can no longer fuse again.
The Rou Kaioshin says that you can only fuse once. But the way it's worded it could mean that the person you once was can't fuse with another because you won't be yourself anymore. I.E. Goku can only fuse once because afterwards he won't be Goku anymore.
Rou Kaioshin: "Also, you can use the Potara only once in your lifetime!"
Goku: "Oh... Did you use it with someone else too...?"
Chapter: 502 (DBZ 308), P1.4
^Above is the VIZ big translation. I have added the raw panel as well just in case you want the Japanese. I don't have a translation for it myself. Sorry.
The answer is YES and NO, it all depends on which Akira Toriyama wants them to be.
Potara Fusion is not just a fusion, it somewhat merge two beings into one, sharing both memories. Unlike the Fusion Dance, even though they have fused into one being, but they still have both performers' conscious, that's why you hear 2 sounds overlapping when fused character is talking.
I saw this example on the wiki, it says:
Have Goku and Vegeta fuse with Potara Earrings, then have Trunks and Goten do the same. Then, have Vegito remove one of his earring and have Trunken do the same, and they'll become Gogetenks. It's like how Supreme Kai and Kibito fused by removing their Potara Earrings. I don't think they've ever said what happens if a Potara fusion removes their earrings, so I assume it would work this way. By that logic, everyone in the DBZ universe could fuse into one ultimate being.
Despite the possibilities of using Potara earrings over and over again to create an ultimate strongest warrior, I think you would probably never see this multi-fused character ever in the DBZ universe, unless the writer is a 12 years old kid.