Title:
The title is pretty interesting I think, I mean I haven't seen another fanfiction called this and while there are versions like this, none are called Carnifex Mansion. I think it's pretty appropriate for a mystery kind of story as well since it has that kind of vibe. The poster helps with that too of course but it's definitely good for the genre it's in. 

Description/Foreword:
I think it's an interesting description because, I assume, in the story you're going to figure out what actually happened to the seven girls and if they were actually murdered or not, ah the glories of mystery stories (even though they can be frustrating sometimes).

One thing though, the word "labelled" is incorrect as far as I am concerned. It has one L not two so "labeled".

Moving on from that, I think it's going to be interesting to see how the mystery unfolds with Woohyun and his cousin going to the mansion despite people saying it's cursed ( know I wouldn't be going there especially because mansions/haunted is a goddamn nope). Hopefully they don't get themselves killed though, that would be unfortunate. 

Plot:
Truthfully, the story wasn't what I expected at all and I'm not sure if that's good or not. I expected more of a haunting kind of story where the ghosts of the girls ed with the two, tortured them in a sense. I didn't expect them to actually be in the story and have dialogue like it was normal. They don't sound dead either, they just sound like regular teenagers, not spirits. I feel like they're just teenage girls playing pranks on two people, it doesn't feel like much of a ghost related thing.

Truthfully, this doesn't seem like much of a mystery story as it does teenagers just trying to remove the two from the mansion. It doesn't have many mystery elements to it. I honestly figured we wouldn't meet the girls until later in the story, that it'd be Woohyun snooping around and getting tormented by them, not them actually acting like they've never died. They just seem too normal for the ghost façade that they have going on right now. So for the plot, I do think it's missing the mystery part to it since it just doesn't seem like it's mystery. Having dead people and a cursed mansion doesn't really make it a mystery story. There's no real puzzling moments so far, sure there's the incident of who trapped Woohyun and who bit him but those are easily revealed and don't really make you wonder much. I think it's because of the fact that the girls are in the story as well and truthfully, I can't keep up with all the characters in the story as there are technically nine mentioned.

Also, I don't see how a 'haunted' mansion would still have electricity especially since this was built in an era where there was no electricity (if it were built before 1879 (around the time the first lightbulb could be used for about 40 hours). The mansion I mean. In the 1920's people have had some kind of electricity, not like today, but I have a feeling the mansion is a lot older than 1920 since that's supposedly around the time the girls died, not sure on that since 1920's is all that is mentioned. And after being abandoned for so long, I really doubt someone is paying for the electricity since no one lives there, alive at least. So I don't think it would have electricity. I think it would be more of a matter on using candles/lighters or even cellphones since that is the era Woohyun is from, the era of technology. I think this is me looking into it too much, god knows why I do that .

Also why would there be someone taking care of the place if it's known to be cursed/haunted? Sounds like a death trap. (It was mentioned that a caretaker was there, don't see why someone would). It seems like the place is abandoned since no one has bought it as far as the readers know.

Writing Style/Flow:
One thing I would avoid using excessively is the "~" because it's kind of odd to use it in writing or stories. While chatting with friends, sure, not a big deal but in writing which is more "professional" (for lack of a better word), I wouldn't use it as much.

There was a lot of dialogue. I mean this isn't a huge issue but I would focus more on details rather than just having a load of dialogue. I feel like a story with too much dialogue can sometimes fall flat on its face for the sole fact that it's harder to picture stuff in your head. Like the scenery, the character's appearances, and so on. I don't know.

I didn't really see any grammar issues in the story, just mainly the weird ~ thing that is going on. So really, no issues here.

As for the flow, I mean, it just jump a little considering it went from Woohyun talking about going to the mansion the next month and then them being there right after (I mean no detail about what happened between months - Woohyun's scheduled jobs, etc [if that makes sense god help me] since it just skips to Carnifex). I feel like the story is kind of going to fast now that I've read the rest of it. I feel as if there's little to no background story to what is happening or who these girls really are. Woohyun isn't trying to really uncover anything about their deaths. He's practically just getting a free home stay from what it looks like.

Characterization:
It's pretty early to be talking about some of the characters. I mean there's too many characters for me to really analyze a lot of them too since the focus isn't just on one character, it's on nine pretty much. Woohyun, we know the basics, like he's into the paranormal and is a ghost hunter and like that. He seems pretty determined and quite stubborn as well.

His cousin, we don't know much about her at all. She's just kinda there right now.

And the ghosts, there's seven on them and I don't even know who is who honestly. When it comes to stories, characters will come and go but it usually focuses on a smaller group of people. Nine to me is a bit much. They all seem like main characters since they are what makes the story pretty much. They're all mentioned constantly but I think it started to focus more on the girl who wasn't against their presence in the mansion. I think focusing on her or maybe one of the girls who don't like them, maybe both of them, would be easier to follow compared to nine of them being major characters. If that even makes sense, it's 4am I don't make sense honestly.

Personal Enjoyment:
I wasn't really hooked into the story mainly because of the fact that it was too different from what I thought it'd be. As I said, I don't really see it as a mystery story since I don't feel like I am questioning anything that's happening and the ghosts of the story seem way too casual and human-like for people who were killed. I feel like there's no suspense to the story either and that's usually important for mystery and horror genres. I do think the story has potential as the story did sound quite promising, I just think how it was executed was missing the mark just a slight bit.