Saga of Tanya the Evil started off as a webnovel on the Japanese site Arcadia before being acquired and published by Enterbrain. A 12-episode anime adaptation aired one year ago, and a follow-up movie is now in the works. This release, which is subtitled Deus lo Vult (“God Wills It” in Latin), is a translation of the first physically published novel.

The 325 pages of this release cover the same ground as the first 4.5 episodes of the anime version, albeit with some events rearranged, a few scenes left out, and a couple others expanded upon. For those who haven't seen the anime version, several factors set this reincarnation-isekai one apart from its peers. Instead of a pure fantasy setting or one predicated on game mechanics, Tanya is born into a setting heavily based on Europe around the time of World War I, just with the addition of magic. Tanya was also much older than the typical teenager before his death, which means that he has vastly more extensive life experience and a different worldview entirely. Tanya's ongoing conflict with Being X also adds an extra twist, giving him a direct link to the one responsible for his fate.

This series also stands out in its thoroughly realized world. The magic system has been very carefully thought-out, as something that can be scientifically analyzed to a certain degree. Spells aren't so much cast as created through the use of formulas, which are channeled through engine-like Computation Orbs to achieve desired effects that include flight, defensive shells, optical illusions, and magically-charged bullets that can detonate like a missile. Flight has a practical ceiling with conventional orbs, and altitude acclimation is necessary when that ceiling is raised. Mages are also thoroughly integrated into the military, commonly serving as artillery spotters, forward assault units, and counter-insurgency experts. In fact, the structure of the military and its tactics are explored in greater detail from top to bottom than in any light novel or anime series I've seen. Even the place of military academies and war colleges has been carefully detailed in the grand scheme of things. The politics and overall strategies of the story also suggest that Zen thoroughly did his historical research before writing this.

Truth be told, he might have almost gone too far. This is a more dense and pedantic read than any other light novel I've seen, so much so that “light novel” seems like a misnomer for its classification. Zen regularly expounds on not only strategic and organizational matters, but also various social, business, and economic theories that Tanya uses to get ahead. Footnotes are sometimes required to understand the end result, and scenes sometimes stretch out far longer than necessary to accommodate all the side commentary. Still, the writing is nothing if not cerebral, and all of these extra digressions do allow the reader to get immersed in why things are happening at a meticulous level.

The writing style choices are also interesting. The perspective shifts around a lot, but the prose always remains detached even from the protagonist's point-of-view, as if he still regards Tanya merely as the body he's inhabiting instead of his true identity. The perspective shifts allow Tanya to be seen from different angles, which has the advantage of thoroughly exposing the vast discrepancies between how Tanya intends his own actions and how they are perceived by others. This allows the reader to fully appreciate the irony of how Tanya's careful efforts to get ahead typically end up working in a far different fashion than intended, and not always to his long-term well-being; one great example of this is how Tanya accidentally succeeds in turning a battalion of mages into an elite fighting force while putting them through a training regimen so brutal that it was designed to get them all to drop out – of course, Tanya was looking for a valid excuse to extend her time away from combat.

For those who have seen the anime, there are a number of differences between the book and the TV series. The novel describes Tanya's early life in more detail, puts the content of the first two episodes in chronological order, and handles a number of key scenes to follow differently. The exact effect of the Type 95 on Tanya is explored in more detail (especially how it might be warping her mind), as is the prestige of the Silver Wings Assault badge. The novel also has a few scenes that the anime lacks, such as one where Being X speaks to other gods, a couple of extra scenes where von Lergen (von Rerugen in the anime) expresses concern about Tanya when various assignments come up, and additional scenes with Zettour and other generals. Whether or not those scenes are actually necessary is debatable, but the most interesting additional inclusions are set decades down the timeline, from the perspective of a researcher studying some mysteries about the Empire during the war that involve White Silver and the 203rd Battalion. These scenes suggest that much more about Tanya's actions was shrouded in mystery compared to the anime. (That being said, the scene from anime episode 2 where Tanya is dressed up for a picture, which is not part of this volume, is apparently in the second volume.)

The physical release of the novel stands out from other light novels for its dark gray cover. The opening glossy pages include a map of alt-Europe and an early timeline for Tanya. Black-and-white illustrations are scattered throughout, in a bit higher print quality than normal. A six-page appendix includes a detailed explanation of exterior and interior line strategy and a breakdown of the war's history, all with accompanying maps. Then a highly self-referential three-page afterword follows.

Overall, the novel version of Saga of Tanya the Evil is not a light read, and at least some tolerance for military minutiae is required to appreciate it. For those new to the franchise, this story offers a dark, gritty, and philosophical variation on the standard reincarnation-isekai gimmick. For those who have seen the anime, this volume offers enough extra details to be worth checking out.