Unnerving Calm

 
Prerequisite(s): Concentration 1+ ranks, one Diamond Mind strike.
 
Benefit: You can use your Concentration skill instead of your Intimidate skill when you engage in a duel of wills (see page 27). You gain a +4 bonus on skill checks made to resolve a duel of wills. If your enemy chooses to ignore your challenge, you gain a +2 morale bonus on attack rolls against that opponent for 1 round.
 
Source: Tome of Battle: The Book of Nine Swords