The Sweet Bite of Marriage

"You and I are fated mates, bound by the blood pact." Set in the Leonid Kingdom, vampires are worshiped as saviors, and in this country, all nobles possess magic power. However, Serenade was born without any power, and because of this, her family ab*ses her. She had even lost the will to live. But then one night, Alvis, the Lord of the Vampires, approaches her. He tells Serenade that she has Mithril Blood, a mystical blood to vampires, flowing through her veins. For Serenade, a young woman who had hit rock bottom, is this a blessing? Or a curse...?

Source: MangaPlaza