Kiss the Rain. Jewel Bonds, #2

Selsor's only dream growing up was to be a mage, to bond with a warrior and drive back the monsters in the Territories, and live the life his parents had so loved. His dream is shattered, however, when he displays no magic despite possessing the ability to use it. In the aftermath of failing yet another test while all his peers succeed, Selsor is bullied relentlessly-and lashes out with uncontrolled magic, accidentally killing an innocent bystander.
He is banned from using magic for life, his mage jewels blackened, and thrown out to survive on his own. Years later, a pariah slaving away at an inn in the middle of nowhere, he finds his life disrupted by a strange, bold and arrogant knight who has come to solve the mystery of the rain that has not stopped falling in the village for months.