One Sword Brings Joy and Sorrow

What is the secret in the Ancient Sword Tomb? How can it be so magical that people can travel through time? Is this fate or accident? This is a world of cultivation, and there are monks everywhere. Strong monks are respected in the world, while weak monks can only live in an ignoble existence. How can the protagonist live in this world of cultivation with the thinking of a modern person, and live as if he is "respected in the world"?