To be precise, Heavenly King Yao Xi wanted to meet the Palace Master of the Heavenly Mystery Palace. Although Xiao Shi's identity as the Fourth Heavenly King had already been revealed, no one knew that he was the Palace Master of the Heavenly Mystery Palace. His identity as the Palace Master had always been deeply hidden.
Even if Xiao Shi knew that as long as he hid in his domain, no one could threaten him, he did not expose his identity as the Palace Master.
This also made the three demigod Heavenly Kings have no clue about the identity of the Palace Master of the Heavenly Mystery Palace. They never expected that the Sage who occupied the Fifth Domain was the Palace Master.
