Shifter. The Valiant Series, #2

Fire that burns hot enough can turn into an inferno. For Nsi and Beroan, the flames of war just became a wildfire. Beroan is part of a dragon clan intent on watching the world burn. He is sick of the destruction and wants to bring peace. But Sirath is ruthless, and if he learns of Beroan's disloyalty, he will destroy Beroan's family. Truth interrupts Nsi's small village bliss when she discovers the dragons' role in the devastation of her family and childhood.
The return of the dragons sparks her resolve to protect humanity from the wrath of flame and ash. Together, Beroan and Nsi must unite the clans to battle the dragons and save their world. But uniting the clans may only fuel the fire of war, not stop it. Will Beroan and Nsi be able to save their world from the dragon's wrath?