Dynastes, the unleasher

Flying, double strike, menace, trample
Whenever Dynastes, the unleasher attacks, sacrifi- ce any number of creatures you control with total toughness 4 or greater.
Whenever Dynastes, the unleasher attacks, choose one:
•Destroy target creature with power 6 or less
•Tap up to three target creatures
•Target opponent exiles top 3 cards from his or her library, you may play one of them this turn without paying its converted manacost