Oofta
Legend
Then the are an anti-hero for the duration of the scenario.
Is someone that is anti-social transformed into being social because they are forced to go to a party? Being forced to do something doesn't change who you are.
I don't really understand why this is an issue. Play a hero, villain, anti-hero, an anthropomorphic platypus. Why does it matter? Personally I don't care for anti-heroes in games or in entertainment at all for that matter. But I have no problem with people playing what and how they want. D&D doesn't enforce some golden age superhero expectations, it's just a tool to make campaigns.