The act of murder allows you to draw vitality from fleeing souls.
Benefit Whenever you use a coup de grace action to kill a creature (either by damage or through a failed Fortitude save), you gain a number of temporary hit points equal to half your character level (minimum 1) for 1 minute. These temporary hit points do not stack with multiple coups de grace.
Section 15: Copyright Notice – PPC:BoF
Pathfinder Player Companion: Blood of Fiends © 2012, Paizo Publishing, LLC; Authors: Hal Maclean and Colin McComb.