Fight Fire With Fire by Rochelle Paige

The errand the head of Ember Brandt’s coven asked her to run was supposed to be simple. She didn’t mean to break a rule that could get her killed. Using her fire magic to protect herself was done without thought—like breathing.
Dawson Veles was laid back compared to his cousins. Until a powerful demon pondered the death of the woman who was meant to be his. Then the fire-breathing dragon side of his personality literally came out to play.