I just started Dungeon Crawler Carl. In it he fights a Spanish speaking boss. The Spanish is not translated (so far) and if you can read it, it really changes the mood and impact of the entire scene.
Are there any other books that hide significant plot points behind the use of foreign language?
I think it's the innocent impotence. The crawlers all have agency. The former crawlers are stuck in bad contracts, but they're contracts they signed. The system npcs think they have agency. But the monsters made from the people of the planets? They were just inside and are now experiencing disgusting body horror where they're being forced to kill until they're killed.