Talk to the people around here, they’ll give you various items just for being Yuna’s guardian. Also note when you encounter Dual Horns here, I suggest summoning Valefor, they can’t reach Valefor since it’s a flying aeon…thus you’ll just get to attack at Dual Horn without any retaliation.
You’ll eventually run into Belgemine…she’s on the right overpass off the road…you’ll be engaged in a Pokemon battle of sorts by fighting with your Aeons to see which is stronger. Belgemine will pick Ifrit, but his HP is so high that it’s difficult to win. You should be in Overdrive mode, if you can use the Energy Ray twice in the battle then you should win…otherwise cast Blizzard and use Shield when Ifrit is about to attack with Meteor Strike. If you win you can acquire the Echo Ring, but you will receive a Seeker Ring for trying anyways.
You’ll eventually see a Blitzball on the road, instead of kicking it talk with the kid first and he’ll give you three Softs…otherwise if you kick it he’ll just complain. Eventually you’ll reach an Al Bhed shop, and when you save you’ll notice that a Blitzball option opens up. After you’re in the shop head out and talk with Yuna and in the morning you will be greeted by Mr.Rin and he’ll give you an Al Bhed Primer and Mega Potions. Then head out and fight.
This battle will probably be the toughest one you’ve faced so far. It’s main weakness is fire, so hit it with fire spells continously. Have Tidus attack as normal and caste Haste if he has it on Lulu. Summoning is a bit of a risk since he can easily take out both Ifrit and Valefor in one hit with his special attack. Ifrit’s Hellfire can do up to 3500 HP of damage per round, this enabling you to kill him…if you use it twice and continue to attack with fire spells. Every round of 500 HP you do causes him to be pushed back into the edge behind him. However, if you fail to do at least 500 HP of damage you will be pushed back. You won’t lose if you fall off the cliff, but you won’t get anything from Rin. When it falls on it’s back, Tidus and Wakka can do normal damage on it.
If you won, then after the battle Rin will offer you a Chocobo for free. Whether or not you decide to take up the offer on the free chocobo, head up to your next destination. Be sure to keep a close eye on the ground for the Al Bhed Primer Vol. IX. As you approach the gates you’ll be told to stay back…but luckily Maester Seymour comes to your aid and tells the guards to let Yuna and her guardians in. I wish Square wouldn’t make it so obvious that this guy will be the guy you will fight later…the music gives it all away.
Also note, on your way to the Command Center, there is an Al Bhed Primer Vol. X on the left, it’s just left of the save point on top of the platform. You’ll have to go around to get it. When you reach the lift to the Command Center go up and continue on. After talking with Kinoc, pick up the items and head to the red arrow and talk with the man to initiate the fight.
This battle will be tough, as you can tell by the amount of HP it has. Your summons will come in handy in this battle. The arms will regenerate very quickly, so taking them out is somewhat of a waste, but it doesn’t hurt provided you have the MP and the items to replenish. You should attack the head first. Use magic(if you have any of the second level elemental spells like Firaga or Wateraga) against it, and once the head dies attack the arms…so you prevent them from blocking the attacks to the body. If you managed to use the Overdrives of your summons(probably about 4x), then this battle shouldn’t take too long. It’ll use Demi every other round, so be prepared to heal. Have Tidus cast Haste on either Kimahri or Auron so they can attack more often and quickly dispatch of the arms. After the battle you’ll see an FMV of what occurs afterward and you’ll have to fight this guy again. But this time Seymour will help you, and his magic and magic defense is off the roof. Have him constantly use Firaga or Blizzaga on the body(which has only 6000 HP now) and have the other characters just heal or attack. You can use Seymour’s Overdrive in this battle, but it’s the only time you will be able to see it in the game. The second battle isn’t too hard, but after the battle you get an enormous amount of AP.
You’ll soon find out that Kinoc was right, along with Auron, as the machina failed to do much against Sin. Pick up the HiPotion and then talk to Auron and continue up the path.