It’s been some time since I last saw Shuumatsu Nani Shitemasu ka?. So long that I actually forgot it was incomplete and based on an LN series.
While that adaptation apparently ends partway through the third book, I figured I’d make things easy and just jump right to the fourth… and did not end up regretting that decision. Aside from a slight time gap (which presumably contains the details of Chtholly’s final battle), going from the end of there to the beginning of Book 4 is pretty smooth sailing.
While at the time I’d wondered why they never bothered adapting the full work considering how relatively short it is, after reading through this conclusion the reason becomes clear: The story of the first three books is one of a tragic romance. The full story however is one more focused on Willem, the Beasts, the Visitors, and the general concept of ‘loss of home’. The Anime ends where Chtholly’s story does, while the fourth and fifth books conclude Willem’s.
They’re real good.