This fight was easily beaten with PLD/RDM, 2x BLU/NIN, MNK/NIN, WHM, and RDM/BLM. Paladin should pop with Sentinel on while RDM/BLM sleeps the Poison Peiste. Melee should pull Mini's off one by one to the right or left of the Tank, out of range of Aqua Fortis and fight till all are all dead, PLD/RDM should be in full MDB gear and stand with back against the wall at the Shredded Label as Aqua Fortis has a knockback effect. After Poison Peiste have been defeated DD's should only be in range for short time to either WS, use Blue Magic Physical Spells, or can stay out of range to nuke or used ranged attacks.
During this fight Aqua Fortis was only doing an average of 40dmg to the PLD/RDM with -20% Magic Damage Down, Barwater, and Phalanx up. Stoneskin was reletively easy to cast and reduced damage to the point he was easily able to cure himself without assistance from WHM or RDM on cures, but required refresh. Calcifying Mist did around 90-110 damage.