Abraxos, Pyrowarlock

+4: Abraxos, Pyrowarlock deals 3 damage to all creatures opponents control. Tap those creatures.
-4: Abraxos, Pyrowarlock deals X damage to any target, where X is the number of instant and sorcery cards in your graveyard.
-20: Target player loses the game or gains 20 life. Abraxos, Pyrowarlock can be your commander.