This review for The Devil's Curse was done by WhisperOfTheSea.

The Devil’s Curse by AgustD_Hope
Reviewed by WhisperOfTheSea

Title [1/5]
Just by looking at the title, I can already guess what the plot is. It isn’t a creative title because it pretty much explains the point of the story and what the start of the (or the situation) is. 

Description/Foreword [3/10]
There are many grammatical errors, and the structures and flows of the sentences are too quick and choppy. While reading the second sentence, the wording sounds unusual when read out loud. You’ve already started the first sentence with “A new boy” so there is no need to use “This boy” for the second sentence. The third sentence is already dragging the readers into the plot already without them having to start the first chapter. It is too quick and already fast-paced. The fourth sentence makes no sense whatsoever. I think you meant to say “She then learns” not “She the learns”. There is no need for the comma since the sentence isn’t a compound sentence or a complex sentence. In the phrase “he is an Guardian”, it’s suppose to be “he is a guardian” since you only use “an” when the next word starts with a vowel. I don’t see a reason why “guardian” should be capitalized unless it is the name of a certain pack from A.N.G.E.L. I see nothing wrong with the last sentence but the fifth sentence just needs a little fixing. The “s” behind “doorstep” isn’t needed since it’s obvious that you’re directing the sentence towards the boy and Cheonsa.
Your version:
A new boy moves into the apartment below Song Cheonsa. This boy has only come out at night, sitting on his balcony and singing songs. One day, she was attacked by demons but was saved by the boy. She the learns he is an Guardian from A.N.G.EL, sent to protect her from Death and the Devil’s Curse. Will he be able to protect her when war is on their doorsteps? Or will the Devil get to her first and make her his slave like the rest?
Correct version:
A new boy moves into the apartment below Song Cheonsa. He comes out at night only to sit and sing on his balcony. One day, Cheonsa was attacked by demons but was saved by the boy. She learns that he is a guardian from A.N.G.E.L sent to protect her from Death himself and the Devil’s Curse. Will he be able to protect her when war is on their doorstep? Or will the Devil get to her first and make her his slave like the rest?
I do recommend getting rid of or changing “One day, she was attacked by demons but was saved by the boy.” because it ruins the excitement of the entire story itself. Aside from that, the story seems like the supernatural fanfics I’ve been reading lately so it doesn’t really seem original.

Plot/Theme [9/20]
I’m a very picky person of how events in stories transition and I’ve got to say, yours didn’t do much for me. I will add my own opinions as I go over the events that has happened so far. 
Your story starts off with a Prologue in which the angels are being introduced. About this part, the wording and the structure of the sentences were quite awkward for me to read. An example is:
Two people turned to look at a man kneeling.
The way this sentence is formed could be improved so it doesn’t sound too self-evident. Either add emotion to it or more words (or maybe both). Here is my version:
The two conversing angels turned their faces at the source of the voice, confusion lining their faces.
In my version of your sentence, not only would the reader know that the people talking were angels but they could easily imagine the scene in their head. When I first read this part, I thought that it were the demons talking and not the angels. 

While this passes by, the main character Cheonsa is introduced. She talks on the phone which is then transitioning to her work at the cafe. You’ve done a good job on explaining how the cafe works by having the staff prepare the foods. If only you added a little on how the cafe actually works, I would’ve understood more as a reader. I had to search up online how cafes work since I’ve never been to one in my life (sadly).

As the cafe opens for customers, many customers come in and make the staff busy. This clearly helps me imagine how busy the cafe was and I’ll give you kudos on that. There is one thing that I do want to point out when Cheonsa is taking an order. When the man hands Cheonsa the money, 500 won isn’t that much. It is only .40 cents in USD. I’m pretty sure banana milk doesn’t cost that cheap. It must reach a dollar or two which then the won price should be 1800 won, not 500 won. 1800 won is $1.62 (according to the exchange rate on August 14). The same goes for when he hands the main character a 5000 won dollar bill at the cash register counter. 5000 won is only $4 and it isn’t that much. If you’re talking about “Th-This is too much sir.”, then you should add in another zero to make it it 50000 won (which is $45 in USD). Although it would be fine if you went lower it but the only dollar bills I know of are 50000, 10000, 5000, 1000. So keep in mind, for example, $2000 is a lot in the US but 2000 won isn’t a lot in Korea. 

Upon reading the emotional scene in Chapter Three, I noticed that you seem to be telling instead of showing. When I read this part, all I could feel was nothing and nothing tells me something. This is a emotional scene and you’re supposed to use words that make the readers (me for an example) feel and precisely visualize the scene. 
Telling is when you’re stating what the main character is feeling but showing is using gestures and more emotions to add in the scene. I will use one of your scenes as an example.