Using stick-fighting techniques both defensively and offensively, you can turn your parries into counterattacks.
Benefit(s): While you are fighting defensively, as a free action you can select an opponent you have attacked on that turn and prepare yourself to counter one of its attacks. Once per round, when that opponent attempts a melee attack against you and the attack misses, the attacker provokes an attack of opportunity from you, provided that it is within your threatened area. You must use a club, quarterstaff, dan bong, sap, or tonfa to perform the attack of opportunity.
Pathfinder Player Companion: Martial Arts Handbook © 2018, Paizo Inc.; Authors: Thurston Hillman, Mikko Kallio, Jacob W. Michaels, Matt Morris, Daniel Reed, Mikhail Rekun, Mark Seifter, and Jeffrey Swank.