Much to Ser Alberic's surprise, the fugitive Estinien has initiated contact, saying that he has an important matter to discuss with the two of you. Travel to Boulder Downs and await his arrival at the designated rendezvous point.
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Estinien explains that he did not steal the Eye out of treachery, but rather to spare Ishgard from Nidhogg's wrath when the great wyrm returns. Upon realizing that you have been chosen as a second Azure Dragoon, he proposes that the two of you slay the dragon together. Return to the Observatorium and speak with Ser Alberic for instructions on how to procure the armor necessary for the task.
Ser Alberic explains that you must earn your drachen armor as the Azure Dragoons before you did-by trial. Travel to the Ogre's Belly and seek out Ser Brucemont.
You have passed the first trial. Speak with Ser Brucemont and obtain your reward.
The trial continues. Advance to the next chamber and speak with Ser Heustienne and obtain your reward.
Yet another challenge awaits you. Advance further within the cavern and speak with Ser Brucemont.
You have triumphed over the third trial set to you. Speak again with Ser Brucemont.
You have obtained the third piece of drachen armor. Return to the Observatorium and tell Ser Alberic of your success.
Ser Alberic informs you that one final trial awaits you. Travel ti the graveyard northwest of the Steel Vigil, blow a single note with the flute provided to you, and see to the visitor that arrives.
You have slain a mighty dragon of the Dravanian Horde and claimed its skull. Present it to Ser Alberic as proof of your victory.
Upon receiving the skull, Ser Alberic offers congratulations and presents you with the fourth piece of drachen armor. Though the fifth piece remains beyond your grasp, the old dragoon assures you of your readiness to complete your training. However, he would ask you to reaffirm your commitment before proceeding. If you are truly prepared to embark with Estinien to do battle with the great wyrm Nidhogg, speak with Ser Alberic once more.