Chaos sucks.

There, I said it.
You lose all control of your character for several turns (it does wear off Bolivar), the exact opposite thing you want in a battle. I beat the game at mid 50s quite easily, half asleep, and at 3AM in the morning, with PuPu yelling in my ear not to fall asleep or I'll die.

Yeah, it shouldn't be that much of a problem xD

I'd recommend you take Tifa, Cloud, and Red.

With 99 Megalixers you can basically just set your healer to constantly use Megalixers, in this case, I'd recommend Red does the healing, Tifa has Fury and uses 2-Cut/4-Cut, and of course bashes limits. Cloud uses Ultima, and if you have it, Meteorain. Do you have HP Pluses? If so give them all to Tifa until you have 9,999HP.