You can catch your opponents on your weapon and hold them in place.
Benefit: Whenever you damage an opponent with a piercing weapon, you can immediately make a grapple check; success means the opponent is impaled on your weapon and you both gain the grappled condition. While the opponent is impaled, as an attack action you may make a grapple check on your turn at a -4 penalty to damage the opponent with your weapon, even if your weapon cannot normally be used in a grapple.
Normal: You can only attack with an unarmed strike, natural weapon, or light weapon against opponents you are grappling.
Pathfinder Chronicles – Cheliax: Empire of Devils Copyright 2009, Paizo Publishing, LLC Authors: Jonathan H. Keith, Colin McComb, Steven E. Schend, Leandra Christine Schneider, and Amber E. Scott