Your attacks afflict your foes with the relentless fatigue of a winter storm.
Benefit: A number of times per day equal to your Wisdom modifier (minimum 1), when you use Vital Strike (or Improved Vital Strike or Greater Vital Strike), your strike saps the strength of your opponent. The creature hit must succeed at a Fortitude save (DC = 10 + 1/2 your character level + your Wisdom modifier) or become fatigued for a number of rounds equal to your Wisdom modifier (minimum 1). You can choose to use this ability as a free action after you hit the target with the attack. This is a supernatural ability.
Pathfinder Roleplaying Game Advanced Class Guide © 2014, Paizo Inc.; Authors: Dennis Baker, Ross Byers, Jesse Benner, Savannah Broadway, Jason Bulmahn, Jim Groves, Tim Hitchcock, Tracy Hurley, Jonathan H. Keith, Will McCardell, Dale C. McCoy, Jr., Tom Phillips, Stephen Radney-MacFarland, Thomas M. Reid, Sean K Reynolds, Tork Shaw, Owen K.C. Stephens, and Russ Taylor.