Sirian's Masterstroke

Once per round when you hit a foe you have successfully feinted against via a melee attack using an Aldori dueling sword, you deal an extra 2d6 points of precision damage. When your base attack bonus reaches +11, this damage bonus increases to +3d6, and at base attack bonus +16, it increases to +4d6. This precision damage does not stack with damage from sneak attack, a vigilante's sudden strike, or similar effects. Any effect which protects against sneak attack damage also protects against this additional damage.