If Ning Que wanted to break out of the cliff cave where he had been imprisoned, he had to first solve the inhibition that the Headmaster had left at the entrance. He did not dream of being able to defeat the Headmaster, and could not bear to get rid of the Great Spirit in his body. Therefore, he could only choose the second method. He had to change the Great Spirit and make it get along with the Qi of Heaven and Earth in nature. He had to make sure that they were one and completely wipe out the difference between the two.
According to Origin on Primordial Qi of Nature, the Qi of Heaven and Earth in nature, the Qi in the bodies of cultivators of the Devil's Doctrine and the Great Spirit were essentially the same. However, as time passed and due to the differences in substances, they eventually grew to have different characteristics.