This adventure is about how a folk hero monk became what he is now and his ideology. If adventurers wish to become his disciples, they must spend a decade as acolytes, or else they have to demonstrate their martial prowess against the old monk and his students. This is a non-lethal fight (as written). And I think it is interesting to include events where the party must fight, but the consequence of losing is not death. This way you may go over board with the foes.
He may be the last remaining person to know an ancient technique or fact.