The Yellow Spring Heavenly Fog has a strong corrosive power that can erode even True Qi and souls. Once the Yellow Spring Heavenly Fog enters the body, it's basically a matter of life and death.
"Unexpectedly, my Heavenly Tribulation during my transcending mortal tribulation actually presents a Heavenly Tribulation Phenomenon!"
Even in the case of a common special physique, a Heavenly Tribulation Phenomenon may not necessarily occur during heavenly tribulation. Only those with powerful special physiques will experience a Heavenly Tribulation Phenomenon.
Wu Dao's physique is a Samsara Physique. When he broke through from Heavenly Martial Realm to Martial King, a Heavenly Tribulation Phenomenon appeared in his heavenly tribulation.
The appearance of a Heavenly Tribulation Phenomenon indicates that the individual undergoing the tribulation has a talent that is already so formidable that even the heavens feel wary, and attempt to annihilate it.