I forgot I finished this a long time ago, but never got around to putting in the review... (thank goodness for internet history) but since I'm getting other things out of the way too I thought I might as well do it now.
I did enjoy it, but it was right around here that it started giving me a rather Tower of God feeling; continuing and getting more complex while seeming to perpetuate and perhaps not even go anywhere. Or at least, setting up to go on forever. Also, the translation on these later installments were a bit rougher back then and harder to follow.
As for the story itself? It's still a world I love looking into, but this one featured a lot more teasing of progression than actual progress. It did feature one of the most interesting fights in this series, which for a light novel is pretty good, but in terms of characters it felt a little lacking. Endou has gotten a little bit too used to making their characters expendable, imo... but there's a pretty large cast leftover now that bodes well for the next one.
It's been like 3 months since I last read one of these, but I'm actually coming close to the end of where the light novel has been written, so stay tuned I suppose :>