Effect: The witch calls forth the ghost of a humanoid creature with no more than 18 Hit Dice. The ghost has its own personality and desires, but is willing to bargain with the witch, as if she had cast greater planar ally. To seal an agreement with the witch, the ghost requires life energy equal to 1 temporary negative level (this is in addition to the standard payment for the ghost’s service). This negative level persists as long as the ghost remains in the service of the witch; the witch can end the agreement as a standard action, immediately removing the negative level.
Pathfinder Roleplaying Game: Ultimate Magic. © 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.