Since that day we first spoke, the Youth League has been conducting a sphere hunt of its own.Yaibal
He's very proud to be a member of the Youth League and loves doing the salute. If the player visits the Youth League Headquarters in Chapter 2, Yaibal runs around in front of the headquarters and keeps doing the salute every 2 seconds. If Yuna gives the Awesome Sphere to New Yevon, Yaibal becomes disappointed in her, but still has faith in Yuna even tries to call off the fight.
Yaibal follows Wakka when he goes to the waterfalls to summon Yuna back to the village. He comes with a message from the leader of the Youth League, Nooj, with the request of joining their group, but both Wakka and Yuna decline the offer. Yaibal then suggests that she start her own group, but Yuna asks him to leave them. Rikku comes and takes Yuna and Wakka to her ship.
After Rikku shows Yuna a sphere containing an image of a man similar to Tidus, Yuna wants to go search for more information regarding the sphere. When Wakka is doubtful it will come to anything, Rikku asks him of who should do the search, and Yaibal appears, saying that Youth League will take care of this, and that he volunteers to personally request help from Nooj. When Wakka tells him to stop, Yaibal misunderstands, and says that he will return with a full report of the investigation, and leaves.
While Yuna, Rikku, and Paine travel around Spira searching for spheres that would help Yuna in her quest to find Tidus, they come to Mushroom Rock Road where and find the headquarters of Youth League. They meet Yaibal there, ever enthusiastic of being part of the group. Yuna tells Yaibal that she's joining the gauntlet.
If the party sides with the Youth League, he is happy and is later reprimanded by Lucil for spreading rumors that the Gullwings are joining the Youth League. If the party sides with New Yevon, he is disappointed but he still has faith in Yuna so he runs off to call off the conflict. In Chapter 5, if the party sides with the Youth League, when Lucil holds a tournament, Yaibal is the first person to fight the party. He is defeated and when the party wins the tournament, he is proud of the Gullwings. He is among the people listening to Lucil's speech. If the party sides with New Yevon, he is at the bridge at the end of the road talking to the Gullwings before he leaves on the elevator.
Yaibal is fought during a tournament in Chapter 5, and also appears within the Fiend Arena.