Undoubtedly, when Zhou Tian discovered that the zombies' power weakened more and more after reaching the surface, he was quite excited at the time. After all, whether the zombies were slightly stronger or weaker, he could eliminate them with a single attack.
But undoubtedly, if there was a more effortless method to solve the problem, it's safe to assume no one would choose the harder way to resolve the issue, right?
Given the situation at the time, if Zhou Tian could wait until the zombies' power weakened before striking, he would likely save quite a bit of energy while killing those zombies.
Upon making that discovery, Zhou Tian naturally had no reason not to make use of it.
Thus, when Zhou Tian realized that the zombies would weaken once they reached the surface, he decided not to rush into action against them as they climbed out from underground.
