You’ve learned how to use improvised items as weapons while performing kenki/blitz techniques.
Prerequisites: Catch Off Guard, Improved Unarmed Strike, Kenki or Blitz Technique class feature, Base Attack Bonus of +4.
Once per round, when you successfully hit with a Blitz or Kenki Technique, you can make an additional attack that can be an unarmed strike or weapon attack with an improvised weapon that is on your person (such as hitting an enemy with the strap of your backpack or with the scabbard of your weapon) with a -2 penalty. The improvised weapon can be drawn as a free action during the attack with your off-hand if it is free. If you hit with the additional attack, it deals unarmed strike damage or the appropriate damage of an improvised weapon of it’s size +1. If you critically hit with the additional attack, the opponent is flat-footed until the start of it’s next turn. This additional attack is still subject to the normal penalties of Two-Weapon Fighting. This additional attack does not stack with other sources that provide additional attacks (such as haste) but can be made in place of those additional attacks if the conditions to make the additional attack are met.