Song Shuhang was aware of the physical state of the "Fourth Dark Heavenly Dao" before him... he even knew the method by which the other could "re-prove its Dao" in a short time, as well as the price it had to continuously pay!
These pieces of information, the moment the "Fourth Dark Heavenly Dao" arrived in the "Heavenly Principle Dimension" and appeared before Song Shuhang, were all displayed in his eyes without omission!
This might be related to the "Heavenly Dao Authority" that can perceive the essence of all things—however, logically, this perceptive authority should have been neutralized by the Dark Heavenly Dao, which had equally evolved to become the "Flawless Heavenly Dao."
Even to prevent his greatest secrets from being captured by Tyrannical Song and Senior White and targeted by Tyrannical Song, before stepping into the "Heavenly Principle Dimension," the Dark Heavenly Dao should have shielded or even altered its own information.
