October Novel Prep Challenge

No. Villains are people out to do something they know, deep down, is wrong, even if they feel it is right.

An antagonist is just opposed to the protagonist.

Think of a romance love triangle. The story is focused on bill trying to get with Jane. But there is also Pete who likes Jane. he's not a bad guy, but he is opposed to Bill because they want the same thing. This story can be compelling because Bill has to win Jane over Pete, but Pete is not necessarily a villain. He is just in opposition to (anti) the protagonist.

A villain to be realistic has to think what they are doing is right, even if only right for them (which is where narcissism or sociopathy can come in). They need to be able to justify what they are doing. That can be hard in some cases - think a mass murderer - but it can be found. If you know about the Snowtown Murders, I have interviewed a few of them and know why they did what they did. I don't agree, and society would not agree, but it made sense to them.