Griffith, Falcon of Light

+3: Knights you control gain First Strike, Vigilance, and Haste till end of turn.
-4: You, Knights you control, and Griffith, Falcon of Light gain Hexproof till the end of the next turn. Draw a card.
-15: You may sacrifice all permanents you own on the battlefield except for Griffith, Falcon of Light. If you do, you win the game.