You can stagger and disorient a foe with a sneak attack.
Prerequisites
Fiendish Pact, sneak attack +2d6.
Benefit
When you deal sneak attack damage, you can spend a use of your Fiendish Pact to disorient your victim. The victim becomes staggered for 1d4 rounds. While staggered, your victim suffers a profane penalty to Perception and Insight checks equal to the number of Fiendish Feats you possess.