Your kiai shout can panic your opponents.
Prerequisites: Cha 13, Kiai Shout, base attack bonus +9.Benefit: When you make a kiai shout, your opponents are panicked for 2d6 rounds unless they succeed on Will saves (DC 10 + ½ your character level + your Cha modifier). The kiai shout affects only opponents with fewer Hit Dice or levels than you have.
Source: Complete Warrior, page 99.