Hermaeus Mora

This card costs {1} less to cast for each exiled Black Book.
When Hermaeus Mora enters the battlefield, look at the top {x} card of your
deck. Exile a Black Book from among them. {x} is the number of exiled blackbooks you conrol.
{3}When you cast an instant or sorcery spell, copy it and select new targets for the copy. Exile it afterward.