Wakka takes out the negator first. Tidus, Auron & Lulu on limit breaks. Yuna Grand Summons Ixion. Monster toast.
Ixion should be in overdrive. Sorry, I forgot.
I’m playing FFX right now (not my first time through), and I remember the Crawler/Negator battle. Start by having Wakka kill the Negator (you could also use Rikku’s Use ability if you’ve got any good items in there). Once that happens, the Crawler will start counting down. Once it hits zero (watch the little window on the side of the screen to know when Crawler will attack next after it counts down), it will attack with Mana Beam. In the interim, attack with your strongest characters and spells. You can summon a weak Aeon (Valefor, Ifrit, whoever) to take the Mana Beam hit for you, too. Otherwise, just tough it out and hope for the best. After Mana Beam, Crawler will spit out another Negator, and you do it all again until it dies.
Also keep in mind that Crawler will counterattack during its countdown if you use Thunder magic on him, so keep Lulu or Ixion’s health up if you’re going to use them.
Mercutio: Sucks about the Yunalesca battle. I hated that one too. Try having all your Aeons and Yuna in Overdrive when you start the battle, then fight until you get to her third form. Then use your aeon’s Overdrives, Grand Summoning on the strongest aeon (Bahamut’s a good choice). Aeons are immune to Yunalesca’s Mega-Death attack, and if you’re using their strongest attacks, hopefully you’ll never have to let her attack your characters. Still leave someone in the party in Zombie status, just in case she gets to use Mega-Death on your party inbetween summons.
Re: Mana Beam: I would time it so that the beam would hit one of my Aeons. Better to sacrifice one of them than all 3 of my fighters.
Honestly, this is one of the easier bosses in the game. If you’re having that much trouble, you might consider either restarting or going back and raising levels for a while.
ultrafilter, to be fair, this battle is more about timing than force. It takes practice to understand when to do what. I know it did for me.
Eh, maybe. When I played through FFX, I had already been through 4, 5, 6, and 8 (and most of the way through 1 and 7), so it was nothing I hadn’t seen before.
In fact, as far as boss battles go, I don’t think there was much in the way of things I hadn’t seen before…
A hint that is probably obvious to you, but I’ll say it anyway.
Use your aeons in smaller random encounter battles and let them get hit until they overdrive. Then, dismiss. That way, you are always fully overdriven when you come up to a boss.
Also, boost Yuna’s stats as much as possible, especially strength… her stats affect aeon’s stats.