DFFOO [GL]: Fangs of Promise Pt. 15 (CHAOS) - Cloud, Serah, Warrior of Light (Klay)

Some tips:

Monitor your buffs/debuffs.
Don't get broken! Their single target HP attack is enough to one shot one of your characters easily.

Any one of the synergy gang works well here, obviously (Fang, Tidus, Yuna)
Cloud does way too much damage to not bring, especially if he's purpled. However, be aware, you can't stun these guys. Cloud's Crimson Edge weapon passive provides dispell, which is a godsend for this fight.
Sap helps a lot, although they're immune to it. Get around that immunity with the framed saps provided by either Serah or Sherlotta.
Warrior of Light will protect you, but be aware, the shaman shave the shield down very quickly, so don't hesitate to throw the shield back up.
Good Luck!

I do not own this song.

Song - Trndsttr (Lucian Remix)
Artist - Black Coast, M. Maggie

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(Klay)