For you, impending death is a call to wrath.
Benefit: You are not staggered while using the Diehard feat, but if you take a move and a standard action or a full-round action while you are at 0 or fewer hit points you take 1 point of damage. Further, while using the Diehard feat, you gain a +2 bonus on melee attacks and damage rolls.
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.