The rest area on the Moonflow has a number of shops, although nothing of note is available from any of them. O’aka is also there, on the first screen when you regain control, with a chest right next to him (two Phoenix Downs). O’aka sells some okay equipment, but nothing you should really need to worry about, so ignore him if you want. You can speak to Yuna to learn about a shoopuf experience from when she was younger. Head left to the next screen and speak to Auron to learn about an incident with Jecht ten years ago, then go left one more screen to find a Save Sphere.
Some of your party will be on this screen and behind Lulu will be a chest, containing 5,000 Gil. You can find Maechen here, too, who will tell you tales about the shoopuf and Hypello, if you wish to listen to him. You will be facing a boss pretty much right after the next cutscene, which will take place in the water, so you will only have Tidus and Wakka. If you have any weapons with Lightningstrike for either of them, it’s a good idea to equip them now. Don’t worry if you don’t, though. To continue with the story, head to the middle screen and speak with the Hypello on the raised platform, confirming you want to ride the shoopuf. While the ride is uneventful for a bit, something happens and you’re thrown into a boss fight.
BOSS - Extractor
This fight takes place underwater and you’re forced to use both Tidus and Wakka only. That means you’re short a third party member, as well as someone who can heal using spells, so you will have to resort to Potions and Hi-Potions. As the name suggests, Aqua Shooter is a magical attack that is water-based, so if you happen to have any armor with resistant to Water on it, then you can mitigate that attack somewhat. Upon beginning the battle, the Extractor will use Aqua Shooter twice, then get ready for its next attack.
It does this by rising into the air, but it doesn’t unleash the attack right away, as it will wait until the next turn to do Depth Charges. This attack hits both characters for some good damage and has a chance to inflict Darkness. Thankfully, though, you have a chance to cancel the Depth Charges attack, as long as you deal enough damage to the Extractor whenever it’s rising (around 500 damage or so total). You could also use Provoke to cancel the Depth Charges, but doing this will make Aqua Shooter stronger.
Overall, this is an annoying battle, due to only having two characters and having to resort to items to heal. Tidus should open up the battle by casting Haste on himself, then on Wakka. If you have access to Slow, then you can use this on the boss, meaning that you should get a lot more turns. If things aren’t looking so bad, damage wise, then have Tidus spend a few turns casting Cheer to increase both characters’ strength, as the defensive boost from it shouldn’t do anything for Aqua Shooter and you should be trying to stop Depth Charges. If you gain access to Wakka’s Element Reels Overdrive, try to aim for the lightning hits on the slots.
Note: Oddly enough, Yuna is listed on the results screen after defeating this boss, although there is no way at all for her to gain AP from the battle.
There will be a cutscene after finishing off the boss, then you will be on the northern bank of the Moonflow. Feel free to touch the Save Sphere and save your game, then it’s time to continue. You should see Yuna surrounded by a bunch of people, as well as some of your party members standing around nearby. They won’t say much, but you can talk to them if you want, but head left to the next screen to continue. O’aka will be right next to the Hypello and up the ramp to the right of the same NPC will be Al Bhed Primer Vol. XII. On the third screen is one more chest that contains an Ether.
There’s nothing left to do here, so keep exiting to the left, until you get back on the trail. You will run into someone on the ground and upon approaching this person, you find out it’s someone familiar. Following the scene, Rikku will join your party as the last character. She’s a bit lacking right now, especially in terms of HP, so you might want to stick around on this screen to try and get some Sphere Levels for her. You will also run into a tutorial battle, showcasing chests in battle. Rikku’s special move is Steal, not only allowing her to pick the fiends’ “pockets,” but using Steal on those chests will also get you their contents.
If you attack the chest or end the battle without opening them, then you will lose the contents. In fact, sticking around for some random battles is a great idea, as the chests in the battles can get you a Stamina Tablet and Mega-Potion. These seem to be repeatable, so you can stock up on a lot of the above items. You will also learn about Rikku’s Overdrive, Mix, in the same battle as the chest tutorial. Basically, Mix allows Rikku to mix two items in your inventory, in order to produce a special effect. The game wants you to use the two Bomb Cores from the chest, but you can actually just mix two Potions, if you want to save the other items.
As soon as you round the corner after the above tutorial, there is a chest on the right side that nets you four Antidotes. Right before entering Guadosalam, there will be one final chest, with this one containing a Mega-Potion. You can now enter Guadosalam.