Regula van Hydrus

Regula van Hydrus is a major antagonist in Final Fantasy XIV: Heavensward. The Legatus of the VIth Legion, he seeks the secrets of Azys Lla so the Garlean Empire can use the Allagan knowledge kept within to trap Primals to stop their cycle of rebirth.

Story
Regula is first encountered during the main scenario of Heavensward, when the Adventurer and Alphinaud Leveilleur arrive in the Seas of Clouds in pursuit of Archbishop Thordan VII. Seeking the key to Azys Lla, which is in the possession of the primal Bismarck, he confronts the pair alongside Emperor Varis Zos Galvus, however are forced to withdraw when Lucia comes to their aid in a suit of Magitek Armor.

Later, when the Adventurer's party is able to break the barrier to Azys Lla, Regula ambushes them aboard a massive Garlean airship. Though Ysayle, in her primal form of Shiva, is able to save them and damage Regula's airship, she is slain by an onslaught of firepower. Later, the Adventurer encounters Regula on the surface of Azys Lla, and engages him in battle alongside Alphinaud, Y'shtola, and Estinien. Following this battle, Regula orders his troops to keep them engaged, while he goes on ahead to The Aetherochemical Research Facility. Inside the facility, he engages the Adventurer once more in battle, but flees upon defeat.

Gameplay
Regula van Hydrus is fought as a boss with the aid of Alphinaud, Estinien and Y'shtola at the Dreadnought Landing zone in Azys Lla and later as the first boss of the Aetherochemical Research Facility.

Etymology
Regula's full name translates as "Rule of the Serpent."

Van means "from" or "of" in Dutch (equal to German word von), used by those of noble descent.