A Deathless Empire - Kayla McGrath

Gifted by the Patron of Death, Valine Desdemon is a necromancer by birth, and assassin through training. Approached by King Malik of Adraali, she is reluctantly hired to kill a rival king-one who is trying to form an alliance with the oppressive kingdom she fled long ago.
Willing to be the villain to ensure the continent's freedoms from a tyrannical reign of archaic values, Valine sets off with her shadowy magic to plot the downfall of a country.
But she begins to break her one remaining rule-falling for an employer. And to make matters worse, Malik wants her too.
Fighting against daemon and saint created beasts, the feelings growing for Malik, and prophecies from the stars, Valine begins to have revelations about her magic, forcing her to question who she can trust and what she can do. Because she is the difference between a conquered empire, and a deathless empire.