C664 Past Memories
Rather than saying that it was a cultivation technique, it was more like a cultivation exercise. Perhaps Qing Cheng felt that it wasn't perfect enough, so he sealed it with his will, making it seem as if he was ashamed to see it.
It was recorded that Qingcheng Zi was a person who had lived a long time, but unfortunately, he had not reached the Aurous Core stage even at the age of 300