Okay, this is my thought
things that happen in this book maybe true. about shinigami, sakuya's death, etc
When they said it's just a prank, actually it's really happening.
When Patche burnt the book, it's like she and Remi ready to battle, included Flan of course (she asked "Who is stronger, shinigami or me" not for nothing)
And, there is Komachi outside, why the hell she want to slacking off that far if not for something important, even though the one who take the life not Komachi, but different thing.
ah, and there is Laevateinn in the SDM's rooftop, not sure if it's just for comedic thing.
I don't know about the afterwards tho, maybe that's right if it's telling about Meiling gonna do some shit for Sakuya