Her Soul for a Crown by Alysha Rameera

Anula Ramanayake of Anuradhapura calculated her ascent the moment she was orphaned—when her village burned in an endless war and the gods forsook her prayers. First, she would marry the raja. Then, she would poison him and take the throne for herself and her people. But when an unexpected coup thwarts her careful plans, Anula is left with one desperate option. She offers her soul to the cursed gods she renounced in exchange for the crown.

In the Second Heavens, Reeri the Blood Yakka, the most dangerous and powerful of his clan, hears her prayer. For eons, he’s waited for such a valuable offering—one that could finally give him the chance to kill his divine tormentor and return his fellow Yakkas to their former glory on earth. Reeri accepts Anula’s bargain, tethering them until their goals are achieved, or until they die.

As the war presses on, Anula must move quickly or lose her chance to become the first raejina. But while she is skilled at many things, especially in stopping hearts, the closer she grows to Reeri, the more she finds her own heart at risk. And when the time comes to fight enemies both human and divine, Anuradhapura and the Heavens will never be the same.