The below review may contain SPOILERS.
Art and panelling- 8
Art is consistent and never a dull moment with it. Manga flows pretty smoothly. Good balance of dialogue with the panels . Even during info dumps it didn't felt like it was getting excessive so massive props to artist for that.
Story and plot -7
Story is pretty much thought out from the start with clear start and end in mind. Not a single filler chapter. No attempt to milk it whatsoever. Author did a great job connecting things. From a technical point of view it was good. Oh and there were some decent plot twists.
Characters - 1
I don't think i liked most characters at all or found them interesting. The motivations seems way too forced for my liking and heavily depends on if the reader feels emotional or sympathetic towards the character. This is true for couple of main characters which makes huge part of the manga. Even for the character where their motivation makes sense it felt very generic and tasteless. Although I would like to give one point for Sai since he actually gave a sense of terror.