Blood in the Water(Tome of Battle: The Book of Nine Swords, p. 86)
Tiger Claw (Stance)
Level: Swordsage 1 (One Tiger Claw maneuver), Warblade 1 (One Tiger Claw maneuver),
Casting Time: 1 swift action
The smell of blood drives you into a fury. As you slash into your foe, each fresh wound you inflict spurs you onward.
While you are in this stance, you whip yourself into a terrible rage. When you score a critical hit against an opponent, you enter a near frenzied state from the sight and smell of blood. You gain a +1 bonus on attack rolls and damage rolls. Because this is an untyped bonus, it stacks with each successful critical hit you score.
If you go more than 1 minute without achieving a critical hit, you no longer gain the benefit of the stance.