Distraction

The Guigu Book says that the extreme of yin and the extreme of yang herald ruin.

The Guigu Books are a general term for forbidden texts of the mystic sects, governing the forces of yin and yang. The yang books are the Eight Wastelands, while the yin books are the Ghost Books. Though forbidden, they are not impossible to read; they are simply extremely difficult to understand. Only those with exceptional talent can grasp even a little of them. Yet among those who can, immortals are rare, and mortals nonexistent.

What happened to the two, one yin and one yang?

This novel and its characters are entirely fictional. Any resemblance to actual persons or events is purely coincidental. Do not imitate.