The duo between Chastice and wielder could be described as symbiotic or parasitic, depending on how you look at it. It's unknown for how long Chastice has been around, but the notoriety of her recent wielders has brought her into the public conscience. Most of her previous wielders had short-lived stints and were ultimately unsuccessful.
Prior to teaming up with Prince Duffy, Chastice was locked away in the royal vault at the castle where Duffy resided. She'd been sealed there for the past decade after Pinocchio I targeted the royal family and took the Queen's life, though this history is unknown to Duffy.