I've Been Living for a Thousand Years

Thousands of years ago, a failed scholar accidentally ate the longevity fruit and gained immortality, but his spiritual roots were completely destroyed and his combat power was not as good as that of a mortal. He lived in seclusion in the mountains and opened a school to pass the endless years. Every thirty years, a group of students enters the school and graduates every three hundred years. He sends away one class after another - some ascend to immortality, some die in battle, some become giants in the magic world, and some start a sect. He couldn't remember the students' faces, but he collected the "tokens of life" left by each student and filled the underground library. Every year he would write a letter to all his students, but he would never send it; he would imitate the students' handwriting and leave messages on them, pretending they were still there. The 108th class of students are a group of teenagers with "wasted spiritual roots" who were abandoned by the sect. Shen Mo teaches them "spiritual mechanics" and "formation geometry" - which are actually the basic sciences of ancient civilizations. The teenagers used this knowledge to fight off their pursuers and shocked the world of immortality. At the same time, the "catastrophe of heaven and man" that occurs every three hundred years comes early, new forces rise, and all parties begin to trace the inheritance of the young people. The silent and peaceful life was broken: former graduates returned one after another, some repaying their kindness, some asking for the secret of immortality, some wanting to destroy the evidence, and a student who returned from the dark side accused his "living" of being indifferent to the world. When everyone thought he was a reclusive old monster, the truth emerged - he was just a mortal, but in the underground library, the life records of every student for thousands of years were burning into the power to rewrite the rules of the world.