This Dark Heart by Zeena Gosrani

A sweeping YA romantasy perfect for fans of Sabaa Tahir and Tahereh Mafi. The evocative world of Agraal is a stunning backdrop for this extraordinary love story. In a world where the shadow-like ‘daayan’ stalk the night, the mages of Agraal are the only ones able to defend the realm. So, when Princess Thiya discovers she has the extraordinary powers of a healing mage, she captures the attention of earth mage Isaac. In order to lure Thiya to the frontline to help defeat the daayan, Isaac does the unthinkable, he takes Thiya’s true love Amara hostage. Thiya must make a perilous journey to rescue Amara. But not everything is as it seems and the powers at work behind Amara’s abduction might come from the darkest heart of them all.