Ruby Nightmare Blade

Diamond Mind (Strike)
Level: Swordsage 4, Warblade 4
Prerequisite: Two Diamond Mind Maneuvers
Initiation Action: 1 Standard Action
Range: Melee Attack
Target: One Creature

With a moment's thought, you instantly perceive the deadliest place to strike your enemy as you study her defenses, note gaps in her armour, and read subtle but important clues in how she carries herself or maintains her fighting stance.

You make a Concentration check against the target's AC. If you succeed, the target takes double normal damage. If you fail, you take a -2 penalty on the attack.