Anime-only viewers are getting a bigger treat at the beginning of this episode than they may realize. That 20-second opening montage, which depicts the information Kumoko is exposed to as a result of hitting Taboo Level 10, provides considerably more detail than what novel readers got at this point in the story. In fact, some of the details shown there – especially linking the discovery and use of MA energy to the decline of the world, the existence and sacrifice of an angelic-seeming being called Sariel, that Black's real name is Administrator Güliedistodiez, that he seems very upset about Sariel being crucified, and that something called “The Goddess's Life Support” exists – only gradually spilled out over the next several novels, and in much more piecemeal fashion than this. Granted, that montage does not dish anything for details, so major mysteries still remain, but that was still an eye-opener for even someone who is eight novels farther along than where the story is right now. What can be surmised now is that this game-like system is not a storytelling convenience nor a whimsy of gods; it exists because it is somehow keeping the world from collapsing. That is a big bomb to drop on a game-like isekai setting.
It is not the only crucial revelation in this episode, either. Hyrince finally returns home and explains to Schlain how Julius met his demise. The culprit, interestingly, proves to be the Demon General that I have been calling White. Now we have at least some clue as to why she has always been shown with her eyes closed: her gaze can obliterate even those as strong as the Hero's party. And Hyrince estimates that it was a Rot Attack, which sure sounds like the new Annihilating Evil Eye that Kumoko gained later in the episode, doesn't it? Also, take a very careful look at the shot where she opens her eyes and you may notice something interesting: she certainly seems to have well more than the standard two pupils, based on the number of light circles present. (See the bonus screenshot below.)
Given that, the series certainly seems to be hinting that White, not the Demon Lord, is the future version of Kumoko at the moment. I would be tempted to say that this is another of the series' misdirections, but if you connect that scene with one shot in the opener, that ultimate destination seems more likely. But if so, that begs a metric ton of questions, not the least of which are how Kumoko got to that state and why she is working with the real Demon Lord when she certainly seems resolved to save the world later in the episode (to save her own rear in the process, of course).
The path Kumoko decides to pursue dramatically ups the stakes on other fronts: she has decided that she must confront and defeat Araba to move on. This is a bold move, and Araba shows that he is well-capable of handling even powerful foes, but Kumoko is at least plotting her moves and planning ahead of time rather than just rushing in. She enters another moral gray area with her talk about committing genocide on the bees, but she is correct that they would dramatically hinder her planned strategy. With the face-to-face setting up as the episode ends, it looks like that will be one of the two major scenes that the first cour ends on next week.
The human side also has another significant development: when Fei officially makes a pact with Schlain, allowing Schlain to summon her for aid, Fei also abruptly goes into Evolve Mode. Presumably that has something to do with Schlain now being the Hero, but if I did not already know from the novels, I would be very curious about what her next evolutionary step is. That also tends to suggest that some big event is on the horizon for the human side as well; perhaps time for Hugo to pop back up again?
Anyway, this episode comes with two significant issues. One is that I feel that they are skipping enough about how Kumoko develops some of her tricks and abilities that it may leave anime-only viewers feeling like they are missing something, especially on Kumoko now being able to teleport. Second, Araba now thoroughly underwhelms me visually as a Big Bad, which leaves me with some concerns about the mega-fight next week. I also feel like they are rushing that confrontation a bit now, in the sense that it has not been given enough time to build up. But we'll see how next episode plays out.
Adaptation-wise, this episode dances all around volume 3 of the original novels but includes some hints about the backstory introduced much later. That the story will not finish the human side of novel 3 this cour now seems obvious.