The Four Symbols refers to a group of five guardian spirits. They consist of Meng Zhang, Ling Guang, Jian Bing and Zhi Ming. Each of them represent one of the four cardinal directions and the seasons. As such, they govern and maintain Aileron's state of nature as the seasons change. It is said that their sacred ground is the small island known as Horai Island.
Huang Long is the secret member of the Four Symbols as well as their leader, the Yellow Dragon of the Center and an earth spirit.
The Four Symbols control and protect one of the four regions of Aileron: the northern, western, eastern and southern regions. As they also represent a season, they gain more power during that specific season. The secret fifth member of the group is the Yellow Dragon, Huang Long, who leads them. It is believed that Horai Island is their sacred ground.
The Four Symbols are based on the Chinese constellations of the same name.