Windkeep: The Talon Trilogy (Unabridged‪)‬

Long ago, Milon Redshield, the first warrior-king of Windkeep Castle, brought down a curse on the kingdom for his cruel treatment of dragons, the Goddess Nilene's chosen guardians of nature. Thousands of years later, Windkeep is still burdened with the curse, and Queen Tessia is having to defend her kingdom from repeated assaults by the weather witches and their allies. She turns to her friends and advisors Norbert the Green Mage and Tyrmiss the Last Dragon, to accompany her and a band of heroes in a quest to travel to the far land of Sheonad in order to parley with the witches, and if they refuse to negotiate, then to destroy their city. 

Tessia urges Norbert to use his powers to fight the witches and protect Windkeep, but Norbert is reluctant to do so because he understands that the world exists in delicate balance, and grave and unforeseen consequences result if the balance is disrupted. After fighting a number of battles and suffering bizarre magical transformations, Tessia and Norbert at last come to understand the kingdom of Windkeep can be saved only through the ancient wisdom of dragons.