Chastice is the name of an ancient demon sword who gains power through blood, and whom currently works with Prince Duffy under his alias of Pinocchio II. Throughout history, Chastice has made hundreds of contracts with wielders like him that feed her blood by whatever means necessary, in exchange for some of her hoarded power. The two of them work together to secure their next blood feast, usually resorting to murderous bloodshed.
Technically, Chastice can feed on living targets, animals, butcher's blood, and the like, but she's very persuasive about her preference for human blood, along with eliminating any possible living witnesses.