Dragoons in XIV lore are basically dragon slayers. For an Ishgardian Knight to become a Dragoon, that Knight has to slay a dragonkin and prove the kill to the Holy See. So "Dragoon" is just an honorary title. You don't have to wield a lance or have special jumpy powers. If you want to find out a little more about regular dragoon lore, go talk to some of the NPCs out in Whitebrim. There's one npc in particular who gives you a quest asking you to find the dragon he claims he slew and bring back a bone to prove it to the Holy See so he can become a Dragoon.Â
The Azure Dragoon is something completely different though. Seemingly once a generation the prized Eye of Nidhogg chooses an individual who is destined to "slay Nidhogg." However, this is not a blessing as it is a curse. The Eye of Nidhogg exerts all of its corruptive force over the individual and attempts to sway them into becoming the Dragon's servant. Which is why Dragoon's wear the Drachen Mail. The armor helps protect them from the influences of the Eye. There is most definitely a connection formed between Azure Dragoon and Nidhogg, but what exactly that connection entails is not entirely clear.
The Azure Dragoon is something completely different though. Seemingly once a generation the prized Eye of Nidhogg chooses an individual who is destined to "slay Nidhogg." However, this is not a blessing as it is a curse. The Eye of Nidhogg exerts all of its corruptive force over the individual and attempts to sway them into becoming the Dragon's servant. Which is why Dragoon's wear the Drachen Mail. The armor helps protect them from the influences of the Eye. There is most definitely a connection formed between Azure Dragoon and Nidhogg, but what exactly that connection entails is not entirely clear.
