You are a grandmaster in the use of your chosen weapon. When you hold it in your hands, no foe can stand against you.

Martial

Weapon Focus, Weapon Specialization, Melee Weapon Mastery or Ranged Weapon Mastery, Fighter Level 10

When fighting with the weapon that you choose for this feat, you gain a number of additional advantages. You gain a +4 bonus on all checks made to resist being disarmed. You can wield your weapon against a foe who grapples you without penalty and without first making a grapple check. In this situation, you can take a standard action or a full attack action as normal. When you take a full attack action, you can apply a +5 bonus to any single attack after your first strike. Once per round before making an attack roll, you can instead choose to treat your d20 result as a 10. You gain a +1 bonus to AC.

You can choose this feat only once, for a single specific kind of weapon. The dedication and focus it requires makes it impossible to gain this feat for more than one weapon.