So many weird things in this chapter....
1) Why not persuade the 6 Heroes (or whatever their name is) over and over again in their dreams until they understand that the threat is real alongside convincing MC as well.
2)The architecture of the whole academy is waaaaay toooo wierd, the 2nd set of walls make sense against magic and intruders. BUT WHY HAVE 10 METER TALL WALLS IN THE CITY??? It's way too high, way too thick and doesn't have any defensive positions on it, so if it's to protect the city from magic that went haywire or something in the academy surely the magical walls would be effective enough. Right now they are just debris that can harm the city more.
3) Why is the "Professor" a teenage child? She looks younger than Rina and so far nothing in this story even developed the world for people to be short or that they can have geniuses at a young age. Even our MC only managed to get "sagely" powers in his late 20 to be able to lock himself up and study. I get it that it's the girl from the cover and that it sells in Japan, still hoping that it makes in-universe sense why she is so young or looks so young (like Yennefer in the Witcher series).