@WriteOutofTime
I guess this is kind of a writing tip?? But also really interesting.
Firstly, protagonist does not equal hero, good character, or morally upright decent sorta person. Protagonist means, quite simply, the main character. The person who's story we're reading. The person we're rooting for.
An antagonist does not equal villain or evil schemer. An antagonist is just an anti-protagonist, or the opposing force that keeps your main character from getting what they want. An antagonist doesn't even have to be a person.
A protagonist can be anything. A hero, like your Superman's or your Harry Potters. An anti-hero, like the Punisher or Jay Gatsby or Macbeth. A villain, like Walter White or Light Yagami. These are all main characters of their respective stories and protagonists. They may not be the hero. But they're not the antagonist.
An antagonist can be anything as well. Elsa from Frozen is an antagonist. The storm from Stephen Crane's Open Boat is an antagonist. The antagonist in Captain America Civil War is even less tangible. Antagonists aren't evil, they just keep the protagonist from getting what they want.
TL;DR: An antagonist is not a villain and a protagonist is not a hero. Protagonist and Antagonists are just roles in a story.