Three Mountains [Style]

You are a master of fighting with powerful bludgeoning weapons.

Prerequisites: Str 13, Cleave, Improved Bull Rush, Power Attack, Weapon Focus (heavy mace, morningstar, or greatclub).

Benefit: If you strike the same creature twice in the same round with your heavy mace, morningstar, or greatclub, it must make a Fortitude saving throw (DC 10 + ½ your character level + your Str modifier) or be nauseated by the pain for 1 round.

Source: Complete Warrior, page 114.