Hmm, I truly don't understand how Gustav, a transfer student, could be chosen to be prefect. No offense, Hanged. Prefects are supposed to know the ins and outs of the school to help their fellow students. You can't help your fellow housemates if you barely know about the school in itself. Then, there is also the small fact of prefects having duties to see after their housemates after dinner not socialize with Hufflepuffs.