Continue up the road and you’ll eventually see two of Kimahri’s “buddies”, after the scene continue ahead. Take the time now to equip your party members with the Lightningstrike Ability for the battle ahead. You’ll meet Belgemine again…she’ll summon Ixion so you can only summon Ifrit or Valefor. I suggest you summon Valefor first, his evade rate is very high and that means a lot of missed attacks, and missed attacks build Overdrives very quickly. Two shots of the Energy Ray from Valefor should finish Ixion off. You’ll receive two Dragon Scales if you defeat her, otherwise you get the Summoner’s Soul…which is a consolation prize(as well as the winning prize if you defeat her).
You’ll go through a tutorial on the Summoner’s Soul now, which allows Aeons to learn new abilities. Now continue on and save your game when you reach a save point. After you’ve saved, reach the Shoopuf Handler and ride the Shoopuf. Later you’ll fight a boss.
This battle shouldn’t be too hard. The Depth Charges attack will drain away about 350 HP, so be sure to heal after that. Keep your HP above 600 and you should be fine. When it gets ready for it’s Depth Charges, deal damage to it for about 500 HP to bring it back down to avoid the Depth Charges. Otherwise heal if your HP is too low. Note that only Tidus and Wakka can fight this battle.
After the battle you will be back on the Moonflow. Go to the left and you’ll see a small object on the platform above the Shoopuf Handler, pick it up for the Al Bhed Primer Vol. XII. Continue heading left to the next area.