Well... that would be my fault, sorry! I've been having some busy weeks, but I'm planning on trying to get back on track with everything this weekend, so I'll try to throw some reparo there!
It doesn't have to be a super great villain, could just be something small that could be linked to bigger later! Maybe some uppity goblins who are upset with wizards and decided to prank/take advantage of the school
Me! Sorry I took so long, these days have been busier than expected and with limited access to a PC. But it's there!
I left it open for you to choose some place to sit, but take into consideration that it was a pretty serious and harsh professor the one that arraged it.