Your faerie fire not only illuminates your foes, but it also shows you their weaknesses.
Benefit: While a faerie fire you have cast (not one cast from a spell completion or spell trigger item) outlines an opponent, the DC for that opponent to resist your Stunning Fist attempts increases by +2. If you hit an opponent with a Stunning Fist attempt, and that opponent fails her saving throw, you can render the target shaken for 1d2 rounds plus 1 round for every 5 by which the opponent failed her save.
Pathfinder Roleplaying Game Ultimate Combat. © 2011, Paizo Publishing, LLC; Authors: Jason Bulmahn, Tim Hitchcock, Colin McComb, Rob McCreary, Jason Nelson, Stephen Radney-MacFarland, Sean K Reynolds, Owen K.C. Stephens, and Russ Taylor.