I love this series. For over a decade I hoped it would get officially licensed, but alas. It's a series which is very hard to explain or really promote in an overview because of how the story unfolds and the general pacing. Even so, when it gets going it is something special. Great chaarcters, complex plot, interesting world, and some pretty intriguing themes.
The risks and likely reasons it will never be licensed are pretty obvious though. First, JNC has already taken several risks with older licenses and they haven't entirely panned out. It's unlikely this would be even considered for a physical release in English and that would be the only way seemingly to make this maybe work.
Second, this would be a pretty big commitment. The first main part of the series is 11 volumes and the second main part is 17 volumes and still not finished and hasn't received a new volume in six years, granted the author is pretty busy and there has been some hints from Fantasia recently that it will return soon. That isn't all though as someone pointed out earlier in the thread, there are two side-story titles with crucial information for the second part with one being 8 volumes and the other being 11. I can't imagine anyone would license just the first part without the second, but that would also bring into question the two side-stories, which brings the total volume count to 47. This could be slightly mitigated by licensing the manga adaptation of the 8 volume side-story from Square Enix, but that's still a 4 volume manga to consider.
Third, it's hard to determine if there could be traction for this to get an audience. Unlike some of the older licenses like Orphen, Full Metal Panic!, Slayers, & Earl and Fairy, there wasn't much previously released English material or even much of an English fanbase. Granted cases like Orphen & Earl and Fairy with more of a presence in English-speaking markets still struggle to sell. Even though it did get an anime that was licensed, simulcasted and dubbed by Funimation, that was in 2010. Even though the anime did a mixed job as an adaptation, I probably wouldn't be as big a fan of light novels as I am today without it. But even back then, while there was a bit of a fanbase around it, it always seemed pretty small. There are some fans of Takaya Kagami due to Seraph of the End, but I have my doubts that can be leveraged to help out here.
Regardless of the obstacles, I think the story and quality of the work is worth taking a look at. And hopefully one day it will somehow be licensed for an official English release.
