I can't help but laugh whenever Crowley visits the class. The students' reactions are gold.
I noticed this particular group is consisted by students that would be happy with his visit (in history and alchemist class, anyway, because the flying class showed different reactions from almost all students ), while almost everyone else (with a few exceptions, I reckon) would be freaked out or plant their face on the table (I see you, Prince Leona).
I imagine even when released globally, they would not dub the characters' dialogues/phrases in English, but I certainly hope they would do something to the phrases they said during lessons. Especially when several students are practically roasting Crowley by asking if he has nothing else to do.