Sounding Out the Amphitheatre

“

Alphinaud seems intent on traveling to the Akh Afah Amphitheatre.

— In-game description

Steps

Upon learning that the Akh Afah Amphitheatre may yet harbor your quarry, Alphinaud suggests employing the swiftest means of travel available -- the aetheryte found within the Warrens of Snowcloak. Speak with the House Durendaire guard stationed at the tunnel entrance in the western highlands.

You enter the Akh Afah Amphitheatre, and soon cross paths with its heretical occupants. Though Alphinaud declares his intention to parley, the heretics are not inclined to trust his word, and the encounter quickly devolves into violence -- an unwanted conflict from which you and your fellows emerge triumphant yet frustrated. With naught save the parting words of the retreating heretics on which to rely, you have little choice but to investigate the island known as the Dreaming Dragon. Speak with Estinien at the entrance to the Warrens, and plan the next step of your journey.

Before making for the Dreaming Dragon, Estinien suggests that you visit a group of dragonslayers known as the Convictors who have pitched camp in the region of Twinpools. Speak with the Convictors' leader, Jantellot, and learn what he knows of the heretics and their island lair.

Your meeting with the honored leader of the Convictors serves to convince you of two things: first, that Jantellot is ignorant of Iceheart's movements, and second, that he is only marginally better informed about those of his own men. After freely admitting that his fellow dragonslayers often fail to share information with him, he invites you to question them yourselves.

Upon speaking with Tristechambel, you will enter a straightforward duty fighting sets of enemies alongside Estinien and Alphinaud.

Alphinaud will provide support with healing while Estinien provides adequate DPS as a dragoon. He is also likely to pull aggro from most of the enemies, allowing you to safely attack them one-by-one.
For the first set enemies, focus down the Cane-waving Heretic first to prevent him from healing his allies. Do this again for the second set of enemies that appear.
The final set of enemies will include the boss, Louistiaux of the First Line. Kill his lackeys first before targeting him and finishing the duty.