Harmonia's Kiss - The Dragonfire Novels, #5

Enchanted for thousands of years, the shapeshifters known as the Dragon's Tooth Warriors have awakened to find the world a vastly different place. Their leader, concerned for their morale, dares to take them on a mission to confront the fullness of everything they've lost. Little does Drake realize that this dangerous mission will give him a renewed purpose. And if they succeed these Pyr will have to question everything they thought they knew about the past-and confront a quest for the future.