
Originally Posted by
SeeDRankLou
Doublecast is an ability down Lulu's path. You can go down from Demi, and it will cost you 3 Lv.4 key spheres and 1 Lv.3 key sphere, or you can go down after the -aga spells, and it will cost you 1 or each. It is an ability that lets you cast two black magic spells in a row.
Now, for Braska's Final Aeon (aka Jecht). Have at least one characters (if not all) with armor that has Stoneproof on it. Jecht uses an attack that inflicts Petrify, and if he attacks that characters again, the character will shatter and you are down to two party members. If you can't have armor for everyone, immediately heal any petrified character. A simple strategy is to go into battle with everyone's overdrive full. Start the battle with Rikku casting Super Mighty G (Fire Gem + Lunar Curtain just to name one). Have someone Entrust to Rikku, pull out the two other party members you want to use, then have Rikku cast Trio of 9999 (Door to Tomorrow x2). Then have Wakka do Attack Reels, Lulu do a Fury, and finish with Yuna doing all of her aeon's overdrives, healing as needed in between.
However, if you are having trouble as you say you are, you might not have all the resources to do the above. So here's another strategy. Start the fight with Tidus, Auron, Yuna. Now, you might be tempted to kill the Yu Pagodas. Don't. Why you ask? The pagodas will cure Jecht for 1500 each per turn, as well as cure any status ailment. However, if you kill the pagoda, when it comes back to life, it will cure Jecht for however much damage you inflicted to destroy it. So if you had your strong attacker kill it with a 4000 attack, it will then cure Jecht for 4000 a turn. So, just ignore them. The reason for having Auron out is his Zombie Attack, which you might have unlocked. If you did, this is good, because Auron can use Zombie Attack on Jecht, and the pagoda will harm Jecht. It will heal the status effect, so you will constantly have to use Zombie Attack, but it's quicker damage. So, start the battle with Tidus using Hasteaga, have Auron use Zombie Attack (if not then Power Break), and have Yuna start to cast Protect on everyone. Remember to heal immediately if anyone is petrified. If you try to use an aeon, make sure it's an overdrive because Jecht will more than likely dispatch an aeon in one turn, he has a special move for them. Try to use attack that just hurt Jecht, and not the pagodas. You are given the option to "Talk!" to Jecht with Tidus. Save this until after Jecht pulls the sword from his stomach. The trick to this battle is simply keeping your HP up, staying in Haste, and not letting anyone get clobbered while in petrify. A very effective healing trick is to have Rikku cast Trio of 9999 with Yuna (or someone with Pray) out. Then have Yuna (or that character) cast Pray, and all will be healed for 9999 HP. Also, remember Rikku can use Al Bhed potion and other all party member potions, which sometimes are more effective than Yuna's healing. Save the "Talk!" command that Tidus has until after Jecht pulls out his sword, and his overdrive gauge starts filling up. In this form, his overdrive is the Jecht Shot, which will just obliterate your party (worse than Total Annihilation from Seymour). If you save your two "Talk!" 's for this, Jecht's overdrive gauge will return to zero and his turn will be skipped. You can only do this twice, so if he's still alive and his overdrive gauge fills for a third time, have Yuna block his Jecht Shot with an aeon using Shield. I think that's about it, just keep attacking and saying healed and Hasted.