Say what you will, Zhou Heng actually guessed correctly.
All members of the Dragon Clan, after being born, can enter the Ancestral Pond for their first baptism, where they can awaken a portion of their Bloodline Power, easily seeing their potential for the future, thus determining the strength of their cultivation.
Of course, bloodline does not necessarily determine the future. Some clearly have a strong bloodline yet unexpectedly can never break through the Black Cave Realm, while others with a thin bloodline later overtake, completing a true transformation!
In the Dragon Domain, everyone below the Black Cave Realm is an ant. Just the fact that only those in the Black Cave Realm are worthy of having the dragon surname and holding power makes this evident.
