Garene, Taker of Tongues

+2: Deal X damage to target creature or planeswalker where X is the power of the creature with the most power on your side of the field.
-5: deal 3 damage to all of target player's creature with toughness 3 or less.
-15: All creatures on under your control get a base power and toughness of 10/10 and gain trample until end of turn.