The exorcist was immersed in his thoughts that he didn't notice the pair of eyes maliciously watching him from the darkness that are glowing with an ominous glint in them. Fortunately, he already set up a formation around him in advance so the creature that is secretly watching its prey could only hiss in irritation since it can't attack and devour the exorcist unless the exorcist goes out of the formation that protects him like a barrier.
As to why the exorcist had this barrier of protection, it is to protect him when he fully focuses on setting up his part of the formation later. And this formation could also gather spiritual energy to feed the giant formation that they will set up for the Z City for all the residents' safety and security from yin energy. This spiritual energy is what blocked the evil creature from attacking the exorcist.
