First, apologies for the delay on posting this. I have talked about this final episode extensively in other forums, so it slipped my mind that I had not done a proper write-up here.
After episode 23, I was a bit worried about how the final episode would manage to cover everything that was left in novel 5 without seeming too rushed. But that’s exactly what the final episode did: it powered through all of the key points at a brisk pace, which amounts to a more frenetic episode than normal for this franchise. In the process it brings the human side of the story to a cliffhanger stopping point, while also progressing the spider side to the point where Kumoko formally hooks up with Demon Lord Ariel and baby Sophia.
On the human side, the addition of the Glorias to the battle against Kyouya and Sophia has (as expected) a negligible effect on how the battle plays outs. Even those war machines do not pose much of a threat to those two powerhouses, and Shun and his companions are clearly not in Kyouya’s league any more than they are in Sophia’s. (Exactly why they’re so much stronger is beyond the scope of this series, but will be covered in both cases if there are follow-up seasons; Kyouya’s story is told in novel 8 and Sophia’s is given piecemeal from volume 6 on.) Though hardly good, the CG and battle staging is at least a bit better than in the previous couple of episodes, so the real problem spots here are how both Anna’s sacrifice and Shun’s use of Mercy triggering Taboo are handled. In the former case, the anime has done a poor job of establishing Anna’s importance to Shun (and vice versa), which is a failing compared to the novels and sure to leave anime-only viewers scratching their heads. The latter case may also confuse anime-only viewers, since the series has skipped over Shin using Mercy in three other cases; in the anime, he has only been shown using it for Katia and Anna. Otherwise, the series ends the human side exactly where it does in the novels, though it leaves out one slight detail: Hiiro Wakaba was especially memorable because – despite her reclusive personality – she was universally regarded as the prettiest girl in class.
The spider side is handled better, though the series could have put a little more effort into setting up that Kumoko could survive by transferring her mind to one of the newborns created via the Egg-Laying skill; this was only vaguely hinted at as a possibility a few episodes back. The adaptation is skipping a little in having Kumoko go right to Arachne form, but I saw nothing problematic here about how that sequence is handled. Further, seeing the expressions on Kumoko’s human face as she continues to talk mentally (and not through her human mouth!) was a delight. That dovetails directly into Potimas’s efforts to first take – and then later kill – Sophia, who is revealed to have turned Merazophis into a vampire out of desperation for a protector who won’t die on her.
That part and Kumoko’s ensuing arrival and duel with Potimas (or, rather, the remote-controlled Potimas Terminator (which is, presumably, how he survived being beheaded by Sophia on the human side several episodes back) are also handled pretty well; given the production problems the series was dealing with, I have to wonder if that sequence was originally intended to be done in CG but had to be redone in 2D animation when the CG work broke down. Ariel’s arrival ends that, shows the full extent of Body Brain integrating with her, and shows how the two came to a peaceable working relationship. In other words, while the human side comes down to a cliffhanger, the spider side ends the first major stage of its story and sets up for the transition into the next stage.
On the whole, I can see this episode being a messy experience for anime-only viewers, as it does not resolve much (especially on the human side) and throws out a ton of hooks for future stories. The revelation that the elves are completely the bad guys, rather than just doing some bad things, may also be a bit jarring. As a novel reader, though, I am generally pleased with how both the last episode and the adaptation in general has played out. Yes, the adaptation has had some animation and editing issues that can probably be attributed to a too-ambitious production schedule, and the series would be better if a couple of second-half episodes were entirely redone, but I found it plenty entertaining enough, and enough of a departure from the normal isekai power game routine, to still give the adaptation a favorable rating.