Divine Surge, Greater p. 58
A torrent of divine energy courses through you. With supreme force of will, you channel the energy into a devastating attack even as it saps your mortal form.
As part of this maneuver, you make a single melee attack that deals an extra 8d8 points of damage. In addition, before making this melee attack, you can also decide to take a number of points of Constitution damage equal to your initiator level or lower. For each point of Constitution damage you take, you gain a +1 bonus on your attack roll and deal an extra 2d8 points of damage. After using this maneuver, you are considered flat-footed until the beginning of your next turn.