Destruction Devotion( Complete Champion, p. 57)
Your attacks weaken your opponents' defenses.
Once per day as an immediate action, you can call upon the forces of destruction to weaken your opponents' defenses. If you deal damage with a melee attack (but not a melee touch attack) while this ability is active, you temporarily reduce the struck opponent's armor bonus or natural armor bonus by 1. Reductions from multiple hits stack, to a minimum bonus of+0. If the opponent has both armor and natural armor bonuses, it chooses which one to reduce. Once one bonus reaches +0, the other bonus automatically gets reduced until it too reaches +0 or the effect ends. This effect lasts for 1 minute, after which all armor and natural armor bonuses reduced in this way return to normal. Upon reaching 10th level, you reduce your opponent's armor or natural armor bonus by 2 per successful hit.
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 daily turn or rebuke use you expend.