Part-Time Ghost Job in the Underworld

The way of heaven is lacking, and yin and yang are disordered. The old man straightened his rickety back and said to the young man in front of him: "Boy, take good care of me. It has taken me three hundred years from death to life, and three hundred years to hide the sword. This sword should break the path of heaven, disrupt yin and yang, and break the world. After this sword, you should inherit my name, inherit my ambition, and bring peace to the world."