Rokushiki/Rokuogan

Rokuogan is the secret seventh, and ultimate, technique of Rokushiki.

Overview
The Rokuogan  (六王銃 Rokuōgan?, literally meaning "Six King Gun")  is the secret and ultimate attack of the Rokushiki style. Rob Lucci states that only those who have absolute mastery of the other six skills can have access to this seventh skill.

The user places both his/her fists right in front of the target and launches a devastating shock wave, which seems to have the same power as an Impact Dial or even a Reject Dial (depending on the amount of energy absorbed by the dial), and causing massive internal injuries.