Final Fantasy X is a video game from Square Enix for the PlayStation 2 home gaming console from Sony.
GAMEPLAY HINTS
Defeating Yunalesca
On her third form, try to keep at least one character in Zombie status. This will prevent them from dying when Yunalesca casts Mega Death. Hack at her with physical and magical attacks (such as Holy) on her first two forms. On the third form, use Aeons'/characters' Overdrives.
When Yunalesca is in her first form, just use attacks and magic. With the second form, do the same thing only Heal when you get hit with Hellbiter; or use Auto-Med if available. When she is down to 5000 hit points, summon Valefor and use his Overdrive. When the third form Megadeath attack appears, it will not hit your party members, but it will hit your Aeon instead. Then, just finish her with Holy and other Aeon overdrives.
Get the Celestial Mirror and Yuna and Kimari's legendary weapons. After Seymour 3, get Kimari's Crest then capture all the monsters in the Calm Lands to get yuna's weapon. Get her Crest on Besaid Beach. Then, power up her weapon halfway with the Crest. Do the same for Kimari. Valfor, Bahamut, and Ixion should now be able to do about 23,000 to 24,000 damage.
Get all their Overdrives up, including Wakka's Attack Reels. Start by using his Attack Reels, then use a Aeon such as Shiva that can only do 9999 damage. After the first form, cast Haste on Yuna with Tidus. On the second form, use Bahamut and keep healing him with cure magic if you have it. You should get at least two overdrives from him if you keep healing. After the second form, use the last Aeons to your advantage and kill her. If done correctly, your characters should not have been harmed and you should still have other Aeon Overdrives to burn.