What is the explanation of Shen Water Resources Bureau? What does the word "he" mean here?

Shenzichen is a combination of the Three Rivers Bureau, because Shenzichen has three branches, Shenwei is the water fairy, Wei Zi is the water emperor, and Vision Wei is the water tomb. When the three appear at the same time, the water vapor will merge to form a water bureau. It is generally believed that at this time, the three branches are combined and turned into water energy. Combining means merging, combining.