In the mod, the bigger your doriki, the more Life you gain, but I don't feel a real progression of strength and other statuses. I believe that by gaining a certain amount of doriki the player should gain more Strength, speed, jump, haste and resistance in addition to the extra life.
Master level: upon completing all the missions of your fighting style, the player gains the title of master and your exclusive strikes cause more damage and you will have a buff. example: master swordsman deals 35% more damage with the sword.