Ok, the first idea I have on top of my head is about the setting. I would like the possibility of a prequel, that pretty much gives us free reign on our characters, the Teachers in UA Academy etc. But what is more obvious is that one of the characters...could be the user of One For All. I know that this sounds like a Broken Character waiting to happen, but if the character is either played or controlled by the GMs it could very much become an important and interesting plot element.

By the way, If this starts, I already have my own Quirk that I just cannot wait to put in use.