Having run Halatali more times than I can count, please realize the following:

1) Always kill bombs first. They roam and will aggro at the worst moment. Especially in that long almost empty tunnel leading up to the Peiste fight.

2) Let the TANK open random chests & chain winches. Many randomly spawn mobs. Whoever touches it gets enmity first.

3) IGNORE Damantus adds. They will keep coming & do (minor) AOE damage. They are not a big deal. NOXIOUS are the adds to kill, as their poison AOE dmg is stronger.

SPRITES should always be your priority to kill ASAP. Whenever they're out you can't damage the boss since the sprites are charging the huge pools the boss (Guivre and Tangata) stands on. Once those are dead, the pool vanishes and you can once again attack the boss.

4) Use LIMIT BREAKS! You can use LB on Firemane and Tangata.

5) Don't stand in WATER, Fire pools, or any red zones.