LOL I can see Flood doing that....but wait there's more!!

Another idea I have involves someone creating a Frankenstein Hulk that rampages through the Academy

Another one could have an incident where famous characters from books in the Library come to life. Robin Hood trying to rob the rich students whike the Queen of Hearts is trying to behead people.

Another idea where the Academy itself is suddenly transported to an alternate area. 

Or maybe one where maybe one of Lexcorp or Oscorp's experiments escspe and causes havoc. 

Maybe someone's OC comes from the future and warns them to stop a certain event from happening.