Great Rapid Unarmed Strike(General, Fighter)
Prerequisites: Improved Unarmed Strike, Rapid Unarmed Strike, Weapon Focus (Unarmed Strike), Weapon Specialization (Unarmed Strike), base attack bonus +15
Benefit: You can make blindingly fast unarmed strikes. When you use the full attack action with unarmed strikes you may decide to make two extra attacks at your highest attack bonus. However, if you choose to make these extra attacks, then each attack you make that round (the two extra ones and the normal ones) suffers a -6 penalty to the attack roll.
You cannot use this ability and Unarmed Combat's expanded mastery 6 ability to gain three extra unarmed strikes per round. You either gain one extra attack for a -2 penalty, or two extra attacks for a -6 penalty.