This is a world based on "microscopic cultivation". The monk's Dantian is no longer an abstract sea of qi, but a real microscopic world in which living beings can exist. Monks "cultivate" their own Dantian world by understanding the way of heaven and collecting spiritual objects, and strengthen the spiritual veins of mountains and rivers in it. The more prosperous the Dantian world is, the higher and stronger the cultivators are and the longer their lifespans are. A special "symbiosis contract". When the first ray of spiritual wisdom is born in a monk's Dantian world, a symbiosis contract can be concluded with him. Since then, the creatures in the Dantian (called "Tian Ling") have the same origin as the monks' cultivation, sharing weal and woe. The monk's growth feeds back Tian Ling, allowing him to take form; Tian Ling's growth can greatly accelerate the monk's practice and even give him unique magical powers. However, this kind of symbiosis is extremely rare. Once formed, it is the tightest bond in the world and the most fatal weakness.
