Agira Ryūdōin

is the father of Jakō, Rokkaku and Genshō.

Background
He has fought with Might Guy and was defeated. In the fight he was badly injured and died soon after. His sons tried to take revenge on Might Guy, but in the process they realized that they misunderstood their father.

Trivia

 * The markings on Agira's forehead bear a great resemblance to the Cursed Seal of Heaven.