I used Light, Sazh, and Hope for that fight and finished in time to get four stars I think. The amount of extra damage you do while he's staggered and charging his beam when your party has haste, bravery, and faith is crazy. Plus you kill the faces much faster so the incoming damage during that phase is reduced.
If you go all out damage on him when he's charging, you can partially interrupt his cast which significantly reduces the damage you take. It's something like leaving your party with 50%+ health compared to 10%.