Khadgar, Mystic Defender

: First spell each turn cast by an opponent is countered unless they take 3 damage.
+2: Khadgar, Mystic Defender becomes a 2/2 Raven with Flying and Indestructible. If Khadgar, Mystic Defender attacks draw a card.
-6: Deals 5 damage to each creature target opponent controls. That opponent may sacrifice a land to prevent damage from a creature.