Originally, Jack Clark wanted to see if he could obtain the Bronze Bell without revealing his realm.
Thus, he was not concerned when the 'theft' of the Bell by the Silver-winged Heavenly Ant interrupted his earlier selection process, especially since Sara Williams was leading the Forbidden Army to guard the entrance.
Next, all he had to do was to hold off the other three Guardians, while joining forces with the other two to destroy the Silver Heavenly Ant.
As for the Star Ring Divine Clan, as long as Clive Dale does not want to offend Jack Clark, he will not spread the news about his true realm. Even if it leaks later, that would be a much later issue.
But unexpectedly, today he was still forced to begin a bloody massacre.
At the moment Nuriel 'and the other two' looked on in horror, golden gates began to appear behind Jack Clark, each one darker in color than the previous.