Regardless of whether he was confident in his victory or not, the first thing Zhou Tian had to do when facing those three Corpse Demons was to prepare for the impending battle.
Remaining in the stone chamber wouldn't do. Any one of the three Corpse Demons could pose a threat to him. Given these circumstances, Zhou Tian had to retreat into the passage to avoid being surrounded by the Corpse Demons. Otherwise, if he allowed himself to be surrounded by the three Corpse Demons, his already slim chances of winning would become even slimmer.
Taking a few steps back, just as Zhou Tian retreated to the entrance of the passage, the three Corpse Demons that had emerged pursued him.
Catching up with Zhou Tian in a few strides, and just as Zhou Tian struck a pose, the three Corpse Demons attacked simultaneously, directly forcing Zhou Tian to retreat two steps.
