It's kind of hard to imagine these volumes are roughly 150~200 pages! They read really quickly.
Like the other reviewer said, this volume doesn't ever get so mushy that you're drowning in feels - much like the rest of the series. This much I'm very thankful for.
I don't ever really want to say much about what happens, since some are very sensitive to spoiler alerts - but I can say that this was a fairly good volume. We learn tons about Ren's past and why she hates humans in the beginning and more about her relationship with the Granny nun.
It's almost exclusively back story, so be prepared to slow down a bit, but it's fairly necessary and I'm sure we were all expecting it at some point anyways.
Art is well done, and chibi Ren is super cute!!
Erementar Gerade Vol. 15 is best considered a necessary evil: a slow volume that spends nearly all of its chapters explaining backstory. Though the first two chapters are full of action as Cisqua and company finally defeat the Framboise Honeys (like you didn't see that coming), the rest of the volume is devoted to Ren's past. Ren, trapped in an abandoned village with Cou thanks to a snowstorm, remarks that she is reminded of the village she grew up in, and thus she begins to reveal the true nature of her driving desire to go to Edel Garden.
While it is not surprising to learn that Ren's past was tragic, it is thankfully not overdramatic. It is to Azuma's credit that, despite the sheer number of pages that are needed to tell Ren's story, it never becomes so sentimental or heart wrenching that the reader is annoyed by it. Rather, standard elements - the fear surrounding Ren's power as a Shichiko-Hoju, Ren's self hatred, a kind soul seeing Ren for what she is - are never dwelled upon and used only as long as necessary. Though Ren's story is by no means rainbows and unicorns and sunshine, Azuma deftly weaves in humorous moments, from the wrinkled old ladies who lead the village of Edel Raids, to the clumsy and naively innocent Cia, to Ren's gradual affection for Cia contrasted with her intense dislike for Cia's sweets.
A big upside for readers who are more visually inclined is that the chapters on Ren's past are absolutely filled with adorable and sweet drawings of Ren and Cia (and a couple beautiful insert pages). It's not enough to make the story feel like it's going by faster, but it's definitely enough to be distracting. On the other hand, I found the first chapter of action a little confusing. I've been confused by Azuma's action/fighting art in the past, particularly since it tends to use images rather than characters to convey movement or action, and still haven't quite gotten the hang of it. Luckily, it is never unclear what the outcome of a fight is, so I never feel like I've missed out on too much. The localization group did a good job with the flow and style of the dialogue, though there were a handful of instances where I wished either the text bubbles had been larger or the text itself had been a bit bigger.
There are some interesting plot points that I imagine will be more developed in the next few volumes as Ren draws closer to Edel Garden to reunite with Cia. For example, Cia reminds all the adoring younger Edel Raids that singing is not something that can be taught, because they will discover their own songs. This is probably an obvious reference to the song that links an Edel Raid to her chosen partner or the way an Edel Raid can unleash her own power (as Ren does when her village is attacked by humans), but one that is not explicitly explored in this volume. Additionally, the difference between the immortal Edel Raid and the mortal human is alluded to when Cia falls in love with a human, then leaves the village for a new experiment in collaborative living called Edel Garden.
Overall, I enjoyed the pretty pictures and, since I'd already accepted the necessity of Ren's backstory, appreciated the fact that it was quick and to the point, with a nice sentimental gloss over the top. The first two chapters were understandably overflow from the previous volume, but it still felt like the chapters on Ren could easily have stood on their own. Because of this, the volume is quick and easily digestible.