Meng Hao’s spiritual power was different. It belonged only to him. The spiritual energy of others belonged to Heaven and Earth. By practicing breathing techniques, Cultivators could borrow it. Based on the various stages of Cultivation, the amount of time it could be borrowed varied. However, regardless of anything, all of the spiritual energy would once again return to Heaven and Earth upon death.
It was a cycle. Just like the nine paths in front of the gray-robed old man atop the world tree, it was a rule of Heaven and Earth