I think Remi did something to Flan.

Other than lock her away for centuries?

Maybe wouldn't let Flan read that book along with her. Also the above.

As you can see... Flan's hair is on fire XD She must have "practiced" from Patchy's spell book XD (thus the flames around the image)

why is Sakuya using his middle finger?

Did Remi made Flan cry? >=(

WHY are you just sitting there smiling and not putting out the fire burning Flan's hat/head, Meiling?