My Cook Father is A Martial Master?

Robert Son wants to fight. He is an ordinary man with no training and no way in. Bandits attack him, and Martial God John Miller and Boxing King Arthur Hale save his life. He cooks for the two of them, and the food is good enough that they take him as a sworn brother and start teaching him. He trains for four years and ends up second only to his mentor. He is nearly fifty by then. When the Five Peaks Sect holds its trial for new disciples he sets out for it with his son, hoping for a better future for the boy. On the road he kills a demon who had been picking off Five Peaks disciples, does not register that he did it with one strike, and calls the authorities because he assumes everyone around him has been poisoned. At the trial ground nobody can see what he is. He is laughed at and taken for useless through the first two rounds. He holds out, and in the final match against Lara Letizio he fights at full strength.