Rawn, Yer & Ka, the Hydra

+1: Scry 1, then reveal the top card of your library. If it is a green card, put in into your hand.
-1: Rawn, Yer & Ka deals 3 damage to up to three target creatures or players. Transform Rawn, Yer & Ka.
-7: Destroy all other nongreen, nonland permanents. They can't be regenerated.