What is the use of the copper trident of the Bagua Mirror?

The uses of the copper trident of the Bagua Mirror are as follows

The Bagua Mirror refers to the King Wen Bagua Mirror, also known as the Tai Chi Bagua Mirror. It has always been known as the Feng Shui mascot in China. According to legend, in the ancient times seven thousand years ago, Fuxi began to make Bagua by observing objects and images. Feng shui masters believe that the ability of mirrors to remove evil spirits is first-class. Walking in the streets and alleys, it is easy to find Bagua mirrors hanging on the eaves and walls.

The copper trident is the murder weapon.