Razikale

Razikale, the Dragon of Mystery, was one of the Old Gods, ancient draconic beings said by the Chantry to be imprisoned underground by the Maker for usurping His worshipers. The current Circle Tower in Minrathous was once a Temple dedicated to this Old God.

Background
Razikale is the Tevinter Dragon of Mystery. Worshiped by the Tevinter Imperium of old like his brothers, he is an enormous draconic figure of immense power but has yet to be corrupted by the darkspawn taint. Following the defeat of Urthemiel in the Fifth Blight, he appears to be the next Old God in line to be transformed into an Archdemon.

As the Dragon of Mysteries, it is unknown as to what extent his ancient powers can reach (which would be ironically fitting) besides the typical fire breathes and winged flight in addition to controlling an entire army of darkspawn (if successfully corrupted).