Location Where to find the Chu-Bai Spear in Black Myth Wukong

  1. Defeat Captain Lotus - location is Upper Pagoda in Pagoda Realm
  2. Defeat Captain Sie-Voice - location is Manu Wheel in Pagoda Realm
  3. Talk to Captain Void-Illusion - location is Longevity Road in Valley of Ectasy
  4. Defeat Captain Kalpa-Wave - Also in Longevity Road
  5. After defeating them talk to Third Prince - location is lower pagoda in Pagoda Realm

Craft the spear by visiting any of the shrines
 
  1. Defeat Captain Lotus - location is Upper Pagoda in Pagoda Realm
  2. Defeat Captain Sie-Voice - location is Manu Wheel in Pagoda Realm
  3. Talk to Captain Void-Illusion - location is Longevity Road in Valley of Ectasy
  4. Defeat Captain Kalpa-Wave - Also in Longevity Road
  5. After defeating them talk to Third Prince - location is lower pagoda in Pagoda Realm

Craft the spear by visiting any of the shrines
its Captain Wise-Voice also its Mani* Wheel
 
After defeating Captain Lotus visit Lower Pagoda and interact with the prince to initiate the 4 captain killing questiline. He rewards you with the Spear after the quest ends
 

Gamerpiller has a concise guide on it. Just enough hints to get the entire quest done. The bosses arent that difficult imo