Episodes 1-3 covered book 1, 4-6 book 2, and 7-8 book 3. Episode 9 is starting book 4. Book 7 was released just over a month ago, and book 8 comes out in a few weeks, so it’s a race between the animators and the author.
If it’s a single-cour series, they’ll finish book 5 at the current pace, and won’t have enough material to adapt again until at least the Fall season. If they try for 26 episodes now, they’ll have to pull in the spinoff series about Aiz and company, which has 5 books as of last week.Or go with original stories, in which case it was a mistake to rush through the books; 2 episodes for a light novel leaves out a lot of material. Three episodes was already pretty tight, and risks turning an anime into a highlight reel (like DaiMaou), but it’s been working pretty well so far.
I see special editions of book 8 on Amazon, which suggests the anime is helping sales, and the pre-order for the first disc is at #68 in anime Blurays, so my guess is that they’ll do a second series in the Fall or Winter season.
It continues to be entertaining, but I’m hoping that Bell’s new skill doesn’t turn into an all-purpose “I Win” button, which is unfortunately implied in Hestia’s description of it.