The group of Divine Kings had been dealing with Zhou Tian before, and they had already become deadly enemies. Based on the psychology of those Divine Kings, if they were in Zhou Tian's position and truly had the Ability to eliminate them in the Divine Realm, they would have already taken action to kill the Enemies.
Therefore, since Zhou Tian had grudges with them before but never went to the Divine Realm to cause trouble, it naturally indicates that although Zhou Tian is not weak, he does not have the Ability to cause trouble in the Divine Realm. Thus, since Zhou Tian previously had no Ability to cause them trouble in the Divine Realm, as long as they escaped back to the Divine Realm now, in the minds of those Divine Kings, no matter how powerful Zhou Tian is, he will not be able to do anything to them then.
