In the Tianyuan era, traces of giants appeared in the central part of the Vartania continent. After that, the giants continued to harass neighboring countries, and the war gradually burned to the border of eastern China. In order to fight against the giants, China built the first high wall codenamed: Yulong based on the Canglong Mountains. Later, it built two high walls and deployed them in the interior. Three-dimensional mobile devices and mobile artillery were widely equipped in the mobile troops established by China. The mobile force is divided into the city defense corps and the reconnaissance corps. The former is mainly responsible for guarding the country, while the latter is responsible for exploring the enemy's situation and conducting investigations. Most of the reconnaissance corps is placed on high wall strongholds. The appearance of the elemental giants destroyed the existing world balance. The opportunity to seize the spiritual power of the elements gave various countries the hope of improving their strength and resisting the invasion of giants. However, alliances and games among the great powers resulted from this.
