In this world, when cultivators first cultivated, they had to use their will to mobilize their Inner Breath and condense the Essence Qi in their bodies.
After condensing the Essence Qi, he could use Essence Qi to temper his skin, flesh, tendons, bones, organs, and marrow. After strengthening his body to a certain level, he would be able to withstand the impact of the Spiritual Qi of Heaven and Earth.
Different levels corresponded to different realms. Song Shi was not surprised to find out about this through Ye Mu.
The Great Dao had the same goal. Although they were in different worlds and the cultivation of the basic realms was similar, the cultivation system here placed a lot of importance on the physical body.
This was also destined that the foundation of cultivators would be stronger and they would go further in the future.