Shadow and Bone Trilogy by Leigh Bardugo

Orphaned and expendable, Alina Starkov is a soldier who knows she may not survive her first trek across the Shadow Fold—a swath of unnatural darkness crawling with monsters. But when her regiment is attacked, Alina unleashes dormant magic not even she knew she possessed. Now Alina will enter a lavish world of royalty and intrigue, as she trains with the Grisha—her country’s magical military elite—and falls under the spell of their notorious leader, the Darkling. He believes Alina can summon a force capable of destroying the Shadow Fold and reuniting their war-ravaged country, but only if she can master her untamed gift. As the threat to the kingdom mounts and Alina unlocks the secrets of her past, she will make a dangerous discovery that could threaten all she loves and the very future of a nation.