What was a heavenly rule?
As the name suggested, the Heavenly Rules were rules set by the Heaven Realm.
This was a rule that had existed since the birth of the Heaven Realm. It was an iron law that could not be changed. All living beings had to follow it.
Even in an era where the Heaven Realm disappeared and the Heaven Gate was closed, the Heavenly Rules still existed.
Without opening the Door of Heaven, one could not break through the Heaven Gate. This was the rule set by the heavens. No one could violate it, no one was an exception.
This was also the reason why after the Heaven Realm disappeared, many ancient experts either slept, faked their deaths, or sealed themselves.
That was because if one could not break through the Heaven Gate, they could only waste their lifespan and wait for death.
Only when the Door of Heaven reopened would they be able to break through the Heaven Gate and extend their lifespan.
