Luriana

My family was lost to the cannibalistic vampires who appeared one day, but only my second younger sister (Lylia) survived. However, even my only younger sister becomes a cannibalistic vampire, but she doesn't eat humans. And the protagonist, Luriana, tries to kill the cannibalistic vampires, and she meets a group called the Demon Slayer Corps, who are trying to kill the cannibalistic vampires, and together they try to kill the vampire king, Elden.