Divine Surge, Greater(Tome of Battle: The Book of Nine Swords, p. 58)
Devoted Spirit (Strike)
Level: Crusader 8 (Two Devoted Spirit maneuvers),
Casting Time: 1 full-round action
Range: Melee attack
Target: One creature
Duration: 1 round; see text
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 6d8 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.