Within Black Myth: Wukongs six chapters, players will face over 100 mandatory, optional, and secret bosses. Chapter 3s optional bosses include mini-bosses known as non-bosses. Non-Pure is one of these optional mini-bosses. A disciple of Yellowbrow, Chapter 3s final boss, Non-Pure is a formidable foe. Though optional, Non-Pure gives decent rewards that make tackling this boss well worth it.
https://screenrant.com/black-myth-wukong-non-pure-boss-guide/