Ferret von Waldstein (フェレット･フォン･バルシュタイン Ferreto fon Barushutain) is the adopted daughter of Viscount Gerhardt von Waldstein and twin sister of Relic von Waldstein. She and her brother were experimented on in the womb by Melhilm Herzog of The Organization, in Melhilm's pursuit to create the perfect vampire. Melhilm decided to design a pair of twins - one of which (Relic) he intended to make entirely powerful, and the other (Ferret) he intended to shunt all of Relic's weaknesses onto.