Mari

It's not that she's okay with this, it's just the fact that he unintentionally saved her by this action before she was even born, it made it easier for her to accept this fact, and she also realizes it's literally his "job" and that he's not an evil person. (anymore)

It's fine if a review is a mix of subjective and objective opinions, the writer of this review stated both. It's their opinion that they hated the ending but they objectively expressed the plot holes and problems that happened - in the second paragraph. They addressed a lot of bad things.
You on the other hand were being very subjective when you said you hope they take this review down since the drama is still very good. It's your opinion that the drama is good.
Even if they were being extremely subjective the fact stays that their review is among the most liked, therefore many people think the same about this kdrama and the review holds a lot of value for someone who'd like to give it a try.

It's my favorite show and I rewatched some scenes/episodes a few times and I can confirm he doesn't approach just bad people. If he did, he wouldn't approach the cancer patient's mother who just wanted her young child to be healthy. He wouldn't approach Dohee in the first ep either as she hasn't done anything wrong either. He just keeps searching for people who are extremely desperate and lost. :)

Finished the 5th episode, omw to watch the 6th one and I must say I love it a lot, it keeps me hooked from the beginning!! I am just now realizing how much I like the whole class, all of the actresses play so well, it's probably the strongest thing about this kdrama for me.^^ <3 The soundtrack is outstanding too, it keeps playing in my head randomly lol and the plot is way better than what I expected when I first heard of this drama.

I hope so too, but I really believe he didn't cause it, otherwise he'd not look the way he did. From the preview of ep 13, the madam caused it herself, which kinda makes sense considering her other flashbacks, but why would she kill Do-Hee's parents..
And yes, since he keeps so many clocks in his house and probably used to go through these deals daily then it's no wonder that he doesn't remember..
Well, I hope we'll get to see more in ep 13/14 next week. :(

I hope so too. Happy to interact with another fan of this show. <3

True. Past trope is sure annoying when it isn't done right, but I think it fits perfectly into this story. It now makes more sense why the couple fell for each other "out of nowhere", why she "stole" his tattoo and why was he chosen to be the demon. Yet the story isn't all about the past either and has a great focus on present, so it's nicely balanced.

It's my favorite kdrama and I am just so overwhelmed with emotions after episode 12. <3 I was about to be happy that it ended on a good note and that I could survive waiting a week for next episodes, but since the last minute happened... hahaha. I can't wait a whole week, come on. I do think that he personally didn't take any part in killing them and was just disappointed to see that his victim (the father? or both of the parents?) died sooner before their deal was over.
But now the question comes, what the deal was?
And the way he smirked at Madam Ju, I don't know what to think of that either. I'm not sure if he made a deal with her too afterwards since upon her death he didn't burn it, nor I think he was her killer, but it's obvious that they have some sort of connection. Whereas I understand he didn't connect the parents to Do-Hee (considering the fact he has likely way too many victims), he must've recognized Madam Ju and he surely knows more, so why and what is he hiding from Do-Hee?
No matter what, I'll survive any knowledge as long as they have a happy ending. The lighthearted romance and comedy gives me hope that it can't end badly, but then these intense scenes come and I'm just frightened what fate they prepared for our couple. I never wished so badly for the drama to end happily, please. t.t <3

Considering the disappointment on his face, I think he made a deal with the father and was slightly disappointed that he died before the deal, before the 10 years were over. I think he didn't take part in killing them. I do wonder though what kind of deal it was and why he smirked at Madam Ju like that afterwards. (and I do understand that he might've not make the connection to Do-hee's parents, but why does he hide from her that he knew Madam Ju?)

I don't like this trope either anymore, but I like that in this kdrama, they waited this many episodes before properly showing their past. In other shows they make it a big deal since episode 1, so it doesn't even bother me here, it also took just a half an ep (+ the mini flashbacks, yes) and I really loved it this time. They did a great job not putting all focus just on the past.