Dragon Age: Inquisition - Killing the Storm Coast dragon with Vivienne

Just me killing the Storm Coast dragon, Vinsomer, using Vivienne. Was level 15 at the time and Vinsomer is level 19. Her Knight Enchanter specialization is OP against dragons. My team was: Vivienne, Cole, Dorian, and my Quanari Reaver Inquisitor. Missed the beginning of the battle because of PS4's 15 minute limit on recording.