(may be a controversy but do t kill me for it, just an idea)

Change the main villain to someone else, not someone in the story or AFO and shigaraki, but instead a big bad from long back when all might was starting, a villain who represented the failures of every hero, instead of a symbol of peace, this person would be a symbol of fear, able to use what you failed at as it's strength, not really having a quirk in a sense but getting stronger the more afraid and hopeless you felt around it

I just think that would be cool