First, I should note that this game suffers from what are likely budget constraints. I say this because some of the VA choices are... questionable. Ragou's VA in particular is something of a disaster, with a discordant mismatch between the voice and the characterization. This stands out even more because other choices like Kaen and Diran's male VAs are actually really awesome matches.
I failed to properly articulate what the music in this game resembles at most sometimes... and that would be Persona 5. Something about a number of the tracks resembles the ones seen in that game enough that, in combination with the horrible color choices, made me feel like something was off at a lot of points in the story.
The common route of this game is not particularly long (the game as a whole is not nearly as long as any of Light's other games), but it does serve its purpose. In introduces the primary antagonists, the heroines, the side-characters, and the protagonist while setting the stage for future conflicts. It is functional, more than anything else, and if it weren't for the excellent characterization for Mizuri, Shion, Amane, and Tsubasa, it would be considered bland. Ragou and Kaien, for pure chaotic evil characters, are pretty amusing to watch, despite the fact that they are doing horrible things to people.
My complaint is that there is too much time spent on SOL for a Light game. Yes, there is a sense that you need to know what the characters are losing for it to be poignant when everyday life is disrupted, but the ratio is a bit skewed for this game, considered the golden ratio of SOL to plot and action in any good chuunige is 1:4:3.
Tsubasa is a weird heroine... not the least of which because she is a TS heroine who was once a guy. However, in opposition to this, she tends to be the sexiest of the three heroines due to her characterization (it was intentional). She is also the most 'classic' onmyouji of the two human heroines, using some familiar onmyouji techniques and preferring the bow as her weapon of choice.
Her story is, at least in part, a confrontation with her past, and the primary conflict - for her, at least - is internal rather than external. While there is some buildup to a major confrontation toward the end, it needs to be said that the whimsical nature of the antagonists makes the shift to the final battle somewhat abrupt. In addition, it felt like this path didn't really have the sheer drama I'm familiar with from the company's usual works. It isn't a horrible path, but it does feel more like a Millie path than a Chitose path.
Amane is Hayato's adopted older sister who was raised by his grandfather with him. She is a total brocon and constantly clinging to Hayato when she is with him. However, the best way she can be described when she is away from him is 'cold and competent'. She is a master of kenjutsu and a 'power type' onmyouji, using techniques that fall into the 'open path' style of direct combat rather than the more roundabout styles like Houjutsu (which is basically a preparation is everything), Fuujutsu (the art of binding and sealing), or Injutsu (the art of curses and turning ties against an opponent). It makes sense, since the protagonist takes a lot of his inspiration from her.
Her path is more involved with Kaien, as opposed to the way Ragou was the prime antagonist for Tsubasa's path. You'll discover this during his first appearance, but Kaien is the kind of absolute evil that just deserves a good superhero punch to the face. He likes to make people suffer above all other things, and he finds the hatred people direct his way to be pleasurable. The irony is that, rather than the confrontation with him, Amane's inner conflict with her yandere nature is the bigger draw point of this path. To be blunt, if you played the common route, you'll have noticed the signs of yandere in her actions, and this path brings them out in a big way midway through. Uncharacteristic of Light's usual style, it isn't taken to its logical conclusion, instead being solved with the power of love *vomits*.
Shion's path is far more typical of Light's style, in that it is long, highly-detailed, and has a lot of twists and turns.
Now for some explanation. Amongst the Magatsu, there are thirteen called the Thirteen Demonic Generals, who both possess a humanoid shape and intellect, as well as the ability to touch on one of the Seven Aspects of Creation and use them in a spell that matches their desires. Shion, also known as Saikakou Nue, is one of these. In the distant past, she was sealed away by the founding onmyouji of the Isurugi bloodline (Hayato and Amane's ancestor) during the Heian era. Shion herself is one of the few of her kind that is capable of coexisting with the human race, for reasons that are only illuminated in her path. She is a contrary individual, being something of a tsundere combined with someone who puts on arrogant airs and brags about her abilities to any and all that will listen.
To be honest, I was a bit startled at the huge difference between Shion's path and the other two. While the first third is mostly SOL, almost the entirety of the remaining two-thirds is pure plot and action. There are plenty of good action scenes toward the end (the last two chapters of her path are almost entirely battle scenes), as well as background for Kaien (whose origin story is unbelievably sad) and Shion (whose origins are equally sad, which seems to be typical of most humanoid Magatsu). The ending itself is a tear-jerker, and I was somewhat annoyed at the very last part, for reasons that will be self-evident to anyone who dislikes Ragou.
I'd say this one is on the lower end in terms of quality for a Light VN, even if you don't include the minus points for the character design and VAs. It is ironic that even a low-quality Light game is still better than most of what the rest of the industry can produce, though, lol. Typical of my habits, I have been a bit harsh on this game, as it is in my favorite genre. It isn't going to become one of those chuunige I replay on a regular basis, either. However, it is still fine if you are starved for the genre.
Edit: If I have one thing I wish they would redo (other than some of the VAs and the artwork) it would be making the story somewhat less straightforward. Too many of the conflicts in the story are resolved too easily for a Light game, and there is no foreshadowing or long sides that give life to the characters' hidden sides. In particular, Ragou remains a two-dimensional character to the end, despite being the main antagonist. It is ironic that the nihilistic sadistic demonic priest Kaien has a more filled out character than him.