Treatise on Pestilence

Steam rose and mist coiled, water vapor billowing upward, shifting like drifting clouds, like the breath of heaven and earth. Everyone gathered around Xolotl, listening to His Highness's Divine Revelation.

"Between heaven and earth, all things live, die, and cycle on, and there exist all kinds of qi. They have no form or substance, no color or scent, yet they truly exist. There is yang qi, filled with vitality; there is ordinary qi, changing with the seasons; and there is also pestilent qi, which harms life. Together, they affect the health of the human body!"

Xolotl pondered for a long time, until the setting sun dipped westward, before he proclaimed in a deep voice. Beside him, Nashu took out paper and brush, carefully recording every sacred word of the Divine Revelation.

"...Yang qi falls into our bodies with the birth of an infant, and there it becomes different kinds of life force. Divided into three, it is the sky, earth, and abyss passed down among the priests. The qi of the sky falls upon the head and becomes the Tonalli of the head, holding the divinity bestowed by the Main God and deciding a person's fate. The qi of the earth falls upon the heart and becomes the Teyolia within the heart, containing a person's soul. And the qi of the abyss falls upon the liver and becomes the Ihiyotl within the liver, governing the health of the human body!"

Hearing this, Nashu paused slightly, her expression turning devout.

In the inheritance of the Aztec priests, there was also the concept of the "three powers," though they were sky, Earth Mother, and abyss, as manifestations of the world's divinity. And the human body corresponded to the world, possessing a mysterious connection and likewise holding three kinds of life force, just