Being a seasoned manhwa reader ( cringing while writing this but yeah), I can guess where the plot is going. Ghosts have never been a good thing so I knew something was wrong with the girl. I have a couple of guesses as to why both mcs have strong resistances, could be their dead parents or their sheer wills to keep living ( since both lost their parents and have been living alone for a while). More than feeling scared, i feel like the author is trying to get us to see that people have dark sides to their lives and not every cheerful/outgoing person is happy and successful and that is a realistic painting to the characters. Why the mc stands out is because she genuinely showed that she was lonely and grieving, hence why the ml was attracted to her ( aside from her bold advances)
Funny how we all really get mad at characters but damn, I have had friends who had the personalities of all these characters esp the fl. Codependency is a serious issue among women and I totally get why the fl is behaving like that. And from her pov, she must have felt ashamed to tell Eunho that she was relying on her toxic relationship for other aspects of her life than just companionship. Other characters aside, Do Ah is a very realistic character trope. Being disowned by her father, paying for her brother's education while sacrificing her own, and when she found a little solace in her relationship, the Pandora box was opened. But I don't think she is dumb ( author, please dont make me go back to my own words!) I hope to see her moving on and finding closure with her past insecure self. And I get that having a knight in shining armour makes the story interesting but we all know that guys like Eunho don't exist, so maybe exploring a side where Do Ah realises that she does not need any man in her life and liking Eunho genuinely without the feeling of burdening and depending on him ( which she will as the plot predicts)