Protection Devotion( Complete Champion, p. 61)
You exude an aura that protects you and those around you.
Once per day as an immediate action, you can activate a protective aura. While it is active, you gain a +2 sacred (if your deity is good or neutral) or profane (if your deity is evil) bonus to AC, as does every ally within 30 feet of you. This bonus increases by 1 for every four character levels you possess (maximum +7 at 20th level). This effect lasts for 1 minute.
You can select this feat multiple times, gaining one additional daily use each time you take it. If you have the ability to turn or rebuke undead, you gain one additional daily use of this feat for each three daily turn or rebuke uses you expend