Wardbreaker (The Knights of Alinor #1)

Kyrin is the only person in Alinor without magic. Alone on the city streets, he strives to win fame and escape the shadows—and that means robbing the famous Knights of Alinor.
When Kyrin’s heist goes awry, he stumbles across a witch in the middle of her own crime. She steals the Anchor Key, the artifact protecting Alinor from the magically shifting landscape, and flees—but not before offering Kyrin a place by her side.
To reach her, Kyrin must travel across the shifting landscape of his shattered world.
The Knights are on a witch hunt, too. Determined to save the city, they force Kyrin to join their quest to retrieve what the witch stole.
Kyrin has a choice: getting the girl means condemning the city to destruction.
Saving the city means giving up on his dreams.