Monks can atack without weapons, atack from a distance without weapons, and can heal HP and MP as well as some status alilments. Skills dont cost money for MP to use. In the begining of the game they are a easy way to save on cash. Oh, and dont forget Hamedo, atack the peron atacking you before they can atack you and then they dont even get to atack at all. Works great against knight, even if they block it with thier shield.