Dreos, Vault Guardian

+1: Choose target creature. If it has power 3 or greater, tap it. If it does not, destroy it.
-3: Untap up to 1 island and 1 swamp you control. If you do both, give target creature Deathtouch until end of turn.
-6: Destroy all tapped creatures target opponent controls. If any of them were power 7 or greater, instead you gain control of them.