The main character falls asleep in the middle of class and finds himself as a skeleton with only his head normal in a post-apocalypse. There he first fights against limping skeleton with brain and other of its kind then green giant worm. The more he kills monsters the more he gets stronger and more body parts gets restored. After killing a worm he gets new power(something like durable body).
Then he finds an information center where he learns he is thousands of years in the future. He also learns that he will die at a early age and that one of the students who is experimented human with black mutant hand will start rebellion with other experimented humans. He also learns future cultivation technique which kind of looks like aerobics. After which he is killed by a mutant and wakes up. Later he shares cultivation techniques he learned to advance the present time.
It's like Hoarding in Hell but with cultivation. It's colorful and any progress he makes in the future dream stays with him in real world when he wakes up.