You must give him an offering, but this piece will do whatever it is you want it to do. That's because it holds the presence of a very powerful being called the Cardinal. I know that saying it will do whatever you want it to do seems vague, but that it will literally do anything that you want it do-- any kind of magic at all. It is a dual magic piece and you can check out the details on Youtube: https://youtu.be/Q7x_1JijWHU
