The Last Vampire Princess Wants Revenge

On the night her kind was wiped out, she should have died beneath the holy light.

But she survived.

The demon grand duke who saved her told her that the vampire clan had not been destroyed by the human church, but by the current Demon King, who feared their power. More absurdly, divinations performed by the grand duke's family revealed that she was destined to become the next Demon King, and the strongest in history.

She did not believe the grand duke's story. But for the sake of revenge, she agreed to work with him, almost giving up rest and peace in her quest to gain the power to kill the Demon King.