Magic's Promise by Mercedes Lackey

In this captivating fantasy tale, the protagonist, Vanyel Ashkevron, returns to his family estate after years of serving as a Herald-Mage for the kingdom of Valdemar. As he grapples with the challenges of reconnecting with his family, who struggle to understand his magical abilities and the weight of his responsibilities, Vanyel is drawn into a mysterious and dangerous plot threatening the kingdom. With his loyal Companion, Yfandes, by his side, Vanyel must navigate political intrigue, personal conflicts, and the ever-present threat of dark magic to protect those he loves and fulfill his duty as a Herald-Mage.