What is Mr. Yin Yang?

——?Mr. Yin and Yang, that is, Yin and Yang are born. In the Yuan Dynasty, Yin-Yang Studies were established to teach astrology, fortune-telling, divination, and tomb-telling. Learning such subjects was called "Yin-Yang Sheng". Since the Ming Dynasty, when his studies were abolished, Yin Yang Sheng became the special name for funeral stars. Also known as [Yin and Yang], commonly known as [Mr. Feng Shui].