What is this case in The Amulet? What's the point? I hope I can explain it in detail. thank you

This is the eight diagrams of Tai Chi. Taiji refers to the Eight Diagrams of Yin and Yang, which refers to: Liver Sanlian, Kun Liuduan, Yu Zhenyang, Genfu Bowl, Middle Deficiency, Full Ridge, Upper Deficiency and Lower Deficiency. They represent natural phenomena such as heaven, earth, thunder, wind, water, fire and mountains and rivers. According to Taoism, Tai Chi and gossip mean magical power, and the town is afraid of evil!