Calcifer

Calcifer is a fallen star who was caught by Howl. He didnt want to die so he struck a deal with the wizard. Calcifer got Howls heart and a prolonged life and Howl received full access to all of Calcifers considerable powers. As it turns out neither of them liked it after a while but it couldnt be broken by people who were part of the contract. When Sophie Hatter comes to Howls moving castle Calcifer recognizes that she is under a curse thanks to the Witch of Waste and that Sophie has considerable powers of her own of which she is unaware. To break his own curse Calcifer offers to lift the curse placed on Sophie once she manages to break Calcifers contract with Howl.