They should just make a villain called retcon who changes people's past to make them easy to defeat.
This is actually genius. There have been stories of people from the real world going into the comic world, but why not also make it an unflattering look at toxic fandom? Think of what a sociopathic Lex Luther type from the real world who read comics as a kid and is suddenly dropped into DC or Marvel could do? I envision a miniseries where he ruthlessly builds power and takes down heroes one by one to rule the world.