This volume was almost only fights between Rimuru and his friends against various Empire officers, and the fights were not particularly good, mostly the good guys powering up through various deus ex machina (Hi Ciel !) and then beating up the bad guys. It felt like reading a mediocre battle shonen in book form, so it was very disappointing. It also marks the end of the Eastern Empire invasion arc, but that arc was in my opinion the worse in the series, and I found myself losing interest in it.
This makes me kind of sad, since it was the first light novel series I ever read, and the manga adaptation is still one of my favourite manga. But unlike the manga, the light novels were always plagued by mediocre translation and bad writing, with the author having a strong tendency towards inane infodumps, poor pacing, and boring fights. It had however an interesting plot centred on nation-building and diplomacy, as well as interesting and likeable characters, which is why I originally liked it, but that went out of the window when the Empire arc started, and I am not sure the series can go back on track after this, especially since Rimuru and his followers are now extremely overpowered compared to everyone else. I will still be reading the manga, as I have always found it far better than the light novels, but I probably won’t continue with the light novels themselves.