Arkham, Light of Zendikar

+1: Prayer to the Fallen - Spend an action in combat praying for an enemy that has fallen by your hand last round to gain 1 charge of Piety.
-2: Dazzling Strikes - Channel extra mana into your blade, empowering your strikes with extra damage and the chance to blind their targets.
-X: Angel Bomb - Channel for up to X turns while sourcing prayers from allies, then unleash a wave of powerful radiant energy.