Novel 10 of this side story series marks the 24th franchise novel overall that has been released in English to this point. Of all of those, this may be the best in terms of writing quality and characterization acumen. It minimizes one of the franchise's most obnoxiously persistent flaws while allowing both deeper insight into multiple characters and a compelling, greatly expanded alternate take on events playing out in the main series. In the process it reveals that Bell's interactions with the Xenos may have had a stronger and more far-reaching impact in the wake of novel 11 than what the main series even hinted at.

The novel continues the spin-off's own storyline about dealing with Knossos while also paralleling, occasionally intersecting with, and regularly adding onto the events described in volumes 9-11 of the main series – in other words, the entirety of the Xenos arc, though the emphasis is by far heaviest on volumes 10 and 11. It does not provide the whole picture of what's going on, so this is one of the few points in this spinoff where being fully familiar with the events in the main story is essential. Perhaps the biggest revelation about the Loki Familia side of things is that Finn puzzled together much of what's actually going on with his strong deductive skills, even down to realizing that Liliruca must have a shapeshifting ability; about the only major detail he never realizes is the true identity of the black minotaur, though no one else beyond Bell and the minotaur ever found that out or could have reasonably deduced it. It also reveals the conflicts with the Evils that Loki Familia was simultaneously dealing with during Hestia Familia's efforts to return the Xenos underground, including the introduction in the novels of the Fairy Force, the stunning degree of Riveria's ultimate trick, and the first instance of Loki's top three fighting together as a trio. The novel also revals more complete details about encounters that Aiz and Bete have with familiar faces (although this version of Bete's scene, unlike volume 11 of the main series, does not include Aisha's entrance), and additional heretofore-unknown extents of Hermes' scheming are also laid out. In other words, there's a lot of juicy plot content to digest.

The novel's real treat, however, is its character development. Though he is not the sole perspective of the novel, Finn gets the lion's share of attention for the first time outside of his marriage proposal vignette in volume 8 of the main series. Watching how he reasons things out is more interesting than might be expected, but the novel pushes deeper by delving into his underlying motives, in particular how his push to be a shining light for restoring the pride of his race has boxed him in to a certain degree of inflexibility; because he sees himself as a manufactured hero, he cannot act as freely or follow his heart or instincts like Bell can, and he finds himself jealous of that. This is a particular problem in his realization that he cannot afford to acknowledge intelligent, speaking, even feeling monsters, which makes for a striking irony compared to Tiona, who can afford to acknowledge that only because she's an idiot. As a result, instead of Bell taking cues from Finn, Finn concludes that he has to take cues from Bell and rethink his whole mindset if he wants to be the true hero that Bell is shaping up to be. Fujino Ōmori deserves credit for pulling off this mental transformation without any seeming leap of logic.

Finn is not the only one deeply troubled by the prospect of intelligent monsters. It's also a difficult concept for Riveria to accept, though more for the practical reasons that Bell ran into repeatedly on his side of the story. What starts to change her mind on this is so much more clichéd that it is arguably the novel's one weak point. Finn, Riveria, and Gareth all acknowledge that the biggest potential problem is Aiz's reaction. Volume 9 showed how intractable her hatred for monsters is, and volume 11 of the main series hinted at Aiz's mindset about monsters, but this one makes it clear that the whole core of her belief system is based on monsters being the enemy. Unlike the flashbacks in volume 9, this volume also provides long-awaited tantalizing hints about the circumstances which cost Aiz her parents and the extent to which that has shaped her. The full truth is still vague, but more informed speculation can now be made. The nature of her relationship with Bell, and how it is changing as a result of Weine and the Xenos, is also delved into, including some emotional insight which might not be expected from her. Aiz's final words, which are also the final words of the volume, are a disconcerting note to finish on, but they are carefully justified.

Other characters get involved as well, though in more minor capacities. Lefiya has a prominent role in the Fairy Force scenes and gets a few other scenes but is not a big player overall in this volume. Bete, Tiona, and Tione also all have minor roles this time, barely any more prominent than Loki Familia's second-tier personnel, Dionysius's Filvis, Hermes' Asfi and Lulune, or Freya's Ottar. Revis/Levis and Thanatos haven't been forgotten about on the villains' side, either, though they also have lesser roles than in some previous appearances. Syr's brief appearance is also an interesting one, with Loki's comments about her being an eye-opener.

At 299 pages this novel clocks in on the meatier side of the franchise, with a two-page Afterword in which Omori explains an unfulfilled original intent and a profile of Aiz which provides a skill for her that I don't believe has been mentioned before. The trifold color glossy at the beginning features assorted characters, but neither it nor the interior illustrations are shining examples of light novel art. Perhaps most importantly on the technical front, Omori's bad habit of overstuffing battle scenes is less evident here, though his other annoying writing quirks remain.

If you've read the Xenos arc in the main series, this novel is a highly-recommended complement.