King of scars
(Book)

No one knows what Nikolai Lantsov endured in his country's bloody civil war. Now enemies gather at his weakened borders, and the young king must find a way to refill Ravka's coffers, forge new alliances, and stop a rising threat to the once-great Grisha Army. Zoya Nazyalensky is devoted to rebuilding the army -- but she also has enemies to conquer. Nina Zenik wages her own war to save the Grisha -- and must face the pain of her past. As a dark magic within Nikolai grows stronger, he must journey where the deepest magic survives -- and vanquish the terrible legacy inside him. -- adapted from jacket