I Start Cultivating After Death

When Lu Chen died for the first time, he discovered that the dead have their own world. There, there is no sun or moon, no living people, but it is buried with countless long-lost techniques, secret arts, and inheritances. Even more bizarrely—as long as he survives until dawn in that world, he can open his eyes again. On his first return, he obtained a body-forging technique lost for three hundred years. On his second return, he mastered a forbidden art that no one could cultivate. On his third return, he found that reality had changed. People who had been dead for years reappeared, those who had never known him became old friends, and even history deviated from his memories. Lu Chen gradually realized: every time he dies, the world he returns to might not be the original one. And at the end of that darkness that only the dead can enter, someone has been waiting for him for many years. That person looks exactly like him. — Description from novelcodex.org