Ballad of the Black Flag (FOIL)(ACR)

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
[I] [II] [III] Mill three cards. You may put a historic card from among them into your hand. (Artifacts, legendaries, and Sagas are historic.)
[IV] Historic spells you cast this turn cost 2 less to cast.