Back then, the reason the group of Divine Kings dispersed was primarily because they valued the benefits represented by the Abyss World. Therefore, since the group of Divine Kings dispersed for the control of the Abyss World, Zhou Tian could easily use this factor to lure them into his ambush.
Following that thought, Zhou Tian deliberately guided several Divine Kings towards the so-called 'core' position of the Abyss World, based on the information intentionally exposed by the Abyss World.
Since most of the Divine Kings thought Zhou Tian had fled, they weren't entirely unprepared for him. Still, they were mostly convinced that the likelihood of encountering an enemy attack was slim in the upcoming actions.
Thus, with almost no defenses, if those Divine Kings were to encounter an attack from an opponent like Zhou Tian of such strength without preparation, they wouldn't be ready.
