The Nightblood Prince by Molly X. Chang

Two princes. One prophecy. A fate she cannot outrun.

The night Fei was born, a prophecy was made: she would one day become the Empress of All Empresses.
Torn from her family as a child and raised in the palace to one day marry the Crown Prince of the most powerful empire in the land, Fei has only ever known loneliness. When the opportunity arises to seize her own destiny for the first time in her life, Fei sets out to hunt a legendary tiger, knowing it might cost her everything. What she doesn’t expect is to fall under the mercy of Yexue, the beautiful runaway prince from a rival kingdom. Blessed by the night, harboring a dangerous magic, and capable of commanding an army of deadly vampires, Yexue could be the key to Fei gaining more than just her freedom.
But to outrun destiny, Fei must spark a wave of events that will change the world as she knows it. Torn between two princes and plagued by nightmares of bloodshed, she finds that the stars might be more inescapable—and more irresistible—than she ever considered before. . . .