Born the second daughter of the Shadow Hilt Family, Erze also chose to become a vampire hunter after her beloved sister, Seria. Erze's feeble frame kept her from learning how to fight with swords, but she managed to become known as a hunter with her talents in magic. One day she fell into a trap during an operation and was bitten by a mysterious vampire on the shoulder. Her weak constitution grew worse, and she suffered from frequent headaches and thirst every night. Erze knew what this meant and what would end up happening to her. She hid the bite and tried to find a cure on her own, distancing herself from her comrades in her efforts.