"Heavenly King" was the highest noble status in the First Central Empire. It represented top glory and authority.
However, there were also three levels of Heavenly Kings: lower, middle, and upper.
Even the world-famous Wan Zhaoyi was only a lower Heavenly King.
As for middle Heavenly Kings, they were all important figures in the imperial court. They were second only to the Empress' authority. Not only did they have powerful cultivations, they also controlled large families. They could stir up a storm in the First Central Empire. Each of their moves could greatly affect the entire human race.
There couldn't be more than ten middle Heavenly Kings who regularly appeared in the imperial court.