His Forbidden Choice. The Crown Of Hellena Trilogy, #1

In the empire of Hellena, power is inherited, obedience is enforced, and love is a liability. Nyxara Hale is a demon maid from the lowest district-trained to bow, to serve, and to disappear. When she's assigned to Ashbourne Palace during The Choosing, a brutal competition to select the vampire prince's bride, she expects cruelty. What she doesn't expect is Prince Lucien. Lucien is everything Nyxara should fear: heir to a fascist regime, bound by tradition, watched by a ruthless king.
As noblewomen compete for his crown through calculated obedience and quiet cruelty, Lucien begins to notice the one woman never meant to be seen-the servant who watches, listens, and refuses to look away. As the trials grow darker and rebellion simmers beneath the palace's polished floors, Nyxara becomes Lucien's most dangerous secret. Their connection threatens not only the Choosing, but the foundations of Hellena itself.
Because choosing compassion is treason. And loving a demon maid could cost a prince his throne.