Deng Yin used sacrifices to the Blood Pool to turn the Demonic Path cultivators who sought refuge with him into Blood Gods. He was "demonizing" a portion of the population in advance, for only those who acquired a blood demon incarnation would be able to survive in the future Demon Realm.
Likewise, Shi Feiyang led the immortals through their tribulations and harnessed the power of the heavenly tribulation to "immortalize" those who sought refuge with him.
Powerful earth immortals were already not far from heavenly immortals. Some even possessed greater magical power, but their primordial spirits had yet to reach a state of pure yang.
When they released their flying swords and magic treasures to resist the heavenly tribulation, their energies resonated with it, allowing its power to pass into their bodies as well, tempering their spirit and blood and refining their flesh.
The demon tribulation that followed tempered their minds and dispositions.
Weaker earth immortals did not face the heavenly tribulation directly, but they were still enveloped in its field of power, and tribulation energy passed into their bodies too.
It was like thunder crashing overhead: even without lightning striking them directly, its energy could enter their bodies across the distance, making their scalps tingle and every hair stand on end.
This included the ordinary humans, gods, Monsters, and ghosts on Heaven Beyond Divine Mountain. On the surface, they took no part in undergoing the tribulation, but in truth, they were all within its reach and received its baptism.
Those three years of tribulation were equivalent to Shi Feiyang leading every living being on Heaven Beyond Divine Mountain in cultivation—and in the Daoist School's most orthodox, highest-level dual cultivation of nature and life at that!
They had to cultivate whether they wanted to or not. The tribulation summoned this