You are a master of fighting with powerful bludgeoning weapons.
Style
Weapon Focus (heavy mace, morningstar, or greatclub), Improved Bull Rush, Cleave,
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 + 1/2 your character level + your Str modifier) or be nauseated by the pain for 1 round.