The ancestor of the Feng Clan was the Divine Beast Phoenix. In ancient times, there were many types of Divine Beasts, but eventually, they gradually disappeared from this space-time. Only the Feng Clan remains as a race with the purest Divine Beast bloodline. Therefore, the Feng Clan had the strongest deterrence power over beasts.
In other words, the Feng Clan members are born with the ability to make beasts submit.
Of course, this ability reaches its peak after the awakening of the Phoenix Soul; otherwise, it remains challenging to control beasts that are far superior.
