How would each girl make Remilia's life miserable?
Flandre- being a doofus, destroying everything in her path. Sakuya- Always stalking Remi, forgetting her maid duties. Patchouli- Lazy, passive fatass. Can get mad as hell if you take away her books. China- She actually looks calm enough here. Like Flandre, I can only imagine her practicing her martial arts and breaking a vase or something.