RE: Viruses heroes or villains?

Terminator 2 is not an example of a villain becoming a hero. In this movie, this is a different terminator from the one that was crushed in the original movie.

A much better example is Ebenezer Scrooge from A Christmas Carol. Where someone becomes charitable to others by the end of the book. In Despicable Me the main character is a loveless thief who has a change of heart. In both of these the main character is the villain, however. The best example that I can think of is Captain Louis Renault from Casa Blanca. He is part of the government there that had been going along with the fascists until the end of the movie where he sees an opportunity to turn patriot.