Fade into Violence( Player's Handbook II, p. 79)
While the chaos of battle swirls around you, you rely on your ability to slip into the background to avoid your enemy's notice. Your frightened demeanor and pitiable appearance causes your opponents to seek out other targets.
When you wear no armor or light armor and carry nothing in your hands, your opponents might assume that you are an ineffectual fighter. As an immediate action, choose a single target for this feat. If that opponent threatens both you and one of your allies, that foe strikes your ally rather than you unless he succeeds on a Sense Motive check opposed by your Bluff check. If your foe is larger than you, you gain a +4 bonus on your Bluff check. You lose this benefit if you attack any opponent or target an opponent with a spell. This benefit does not apply to ranged attacks or attacks of opportunity that you provoke. Once you choose a target for this feat, you cannot switch to a new target for the rest of the encounter.