How to beat Giant Cactuar (mission 54) with 5 stars?

I have issues taking down this big cactuar on mission 54 fast enough. This thing keeps hitting me with 10k damage, and I have to paradigm shift to restore health; and I don't get 5 stars because I don't kill it fast enough.

Do you have any good strategy I can come up with to get 5 stars?

Solution 1:

There is a passive skill called Random: Instant Chain. Activate this skill on Sazh and spam Cold Blood from the start of the match until you stagger the Gigantuar.

example:

Solution 2:

DEF / COM / MED easy win

I'm back with an answer of my own.

I just got Snow (Main char for the fight so that leader doesn't die) up to 22k HP, Vanille up to 16k HP, and Lightning up to 14k HP (equipped with the 20-sided dice). I did the entire fight as DEF/COM/MED. Lightning did all the job, after the instant chain and thanks to Genji Gloves.