Slow storyline which does not elaborate much on anything else aside from exorcism related, which fits the title, no complains.
The story can bring out more each other's backstory instead. Maybe it is just me, but I felt it is up to the viewers to decide the relationship between each characters. Either the explanation was not clear or vague for my opinion.

Jang na-ra may be a good actress but her expression felt stiff this time through all episodes (unlike her previous dramas, which I know, was supposed to be light hearted). Might be due to her role in this drama, but I felt it could have improvements on this part (see character development).

However jung yong hwa's acting was surprisingly good in this. You can see that he matured through the episodes tho some dialogues are still tacky. And his friend, I am not sure if he supposed to love yong hwa or not??? I felt some BL going on between them, am I over thinking?

The ending! I do not fancy an ending like a first episode kind. Nothing ever changes and I want a season 2 now.