Since that day we first spoke, the Youth League has been conducting a sphere hunt of its own.
Yaibal is a young man wearing Crusader-like armor.
He's very proud to be a member of the Youth League. He loves doing the salute. If the player visits the Youth League Headquarters in chapter 2, Yaibal can be seen running around in front of the Headquarters and keeps doing the salute every 2 seconds.
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. Then 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 expresses her willingness to go search for the answers regarding the sphere. When Wakka expresses his light disapproval because of lacking solid clues, 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 it, and says that he will come back with full report of the investigation, and then leaves the three.
While Yuna, Rikku, and Paine are traveling around Spira searching for spheres which would help Yuna in her quest to find Tidus, she comes to Mushroom Rock Road where the headquarters of Youth League and meet Yaibal there.
Yaibal is fought during a tournament in Chapter 5, and also appears within the Fiend Arena.