The Heavenly Jiao King initially stayed put, and Zhao Xing had no intention of going, because the King's influence was already somewhat saturated relative to Zhao Xing's original territory.
Many spots around Boka Star Land were occupied by the King's followers, leaving no room for outsiders, and even if there were, they wouldn't get much benefit.
Now it's different, Lu Yuehan told him about the King's plan to shift his exploration focus.
Having unearthed a Thousand Star Vine, the King was eager for more and planned a surprise attack to seize territory from top forces of the Ancient Yan Yue Country.
Thus, the King is recruiting. Zhao Xing, being the Minister of Agriculture and a Marquis, possessing the Purple Light Eight Epochs, wouldn't have any problem serving under the King's banner as a grain officer, avoiding the front lines yet able to explore smoothly. This is indeed a good opportunity.
And Nanluo 21 is Zhao Xing's target.
