Is it part of the Chinese legend of the Age of Floods? Is it something that some people have changed in order to increase its popularity?

The Flood era is the primitive era. There was no written record of the living conditions of the first people in those days, and later generations often relied on imagination, legends and myths to understand them. In modern times, due to the development of history, archaeology, anthropology and geology, an approximate understanding of the Flood era has been deduced.

Well, the so-called Demon and Witch races, modern people make up their own. However, the ancients wrote "Shanhaijing" in the writing of the heavenly emperor Jun, Lingshan ten wizards, nowadays novels in the top ten demon saints, twelve ancestral wizards ah have prototypes in the "Shanhaijing", but people do not hit each other eight poles