The Oblivious Master

The protagonist, an ordinary countryman, is actually a mountain master with overwhelming power. His shredded potatoes are a Celestial Artifact, used to cure the Shaw Patriarch. This earns him the enmity of the Lord of the North, who seeks revenge. He confronts the Lord of the North. In their final battle, he strikes down the Lord of the North from his thunder tribulation with a slipper, annihilating his forces and winning a beauty's heart.