Even though Zhou Tian's strength was much greater than those Heavenly Gods imagined, those Heavenly Gods still had to retreat early. Because although Zhou Tian could block that True God, it didn't mean that Zhou Tian and his group could truly confront the power of the Divine City. If they didn't retreat early, Zhou Tian, relying on his strength, had a certain level of confidence to leave safely, but for those Heavenly Gods, nobody could guarantee their safety.
At the moment, it's because the power of the Divine City hadn't reacted quickly that those Heavenly Gods could ensure their safety. But if the power of the Divine City reacted and brought in other Heavenly Gods from different domains, Zhou Tian naturally would not be in danger, but his subordinate Heavenly Gods likely couldn't leave the Divine City peacefully.
