The Swapped Covenant :The Villainess's Choice

Reborn villainess Seraphina swaps marriage contracts with her gentle sister, marrying the unhinged vampire Duke Cassian to avenge her sister’s past-life misery. Meeting fire with fire, she tames the cruel household and secretly allies with the upright Chief Justice Julian. After exposing Cassian’s treasonous coup and freeing herself, Seraphina finally embraces a true romance with Julian, who has secretly loved her for ten years.