Devil's Aura( Fiendish Codex II: Tyrants of the Nine Hells, p. 81)
Your close association with diabolic powers stains your soul. By focusing your power, you can cause other creatures to become unsettled and nervous in your presence.
You can generate an aura of fear for 1 round as a swift action. All living creatures within 10 feet must succeed on a Will save (DC 10 + 1/2 your HD + your Cha modifier) or become shaken for 1d3 rounds. Multiple exposures to the same aura have no additional effect. The aura lasts for 1 round. You can use this ability a number of times per day equal to the total number of devil-touched feats you have selected, including this one.