Having been through the Master Teacher Continent, Azure, and the Firmament, Zhang Xuan was able to understand how the difference in spiritual energy could affect the lifeforms living in the environment.
The differences between the three worlds lay mainly in the stability in spatial laws and temporal laws and the concentration of spiritual energy.
It was mainly the difference in spiritual energy that resulted in a vast difference in the prowess of their cultivators. That was why lifeforms in the Firmament were mostly born as Semi-Divinities, and with just a bit of cultivation, they could easily become Gods.
The Otherworldly Demonic Tribe carried extremely concentrated killing intent inside their bodies, making them extremely restless and bloodthirsty.
However, through the absorption of the mercury-like spiritual energy in the Azure, the concentrated killing intent within their bodies would be neutralized significantly.