Why is it so difficult to write a mean protagonist? ‘Mean’ as in nasty rather than awesome, not that a mean character cannot also be awesome.
Let’s get straight to the heart of the matter. How do you imagine someone who is totally and consistently mean/nasty, without making them a two dimensional cliche?
The key is to try and imagine why anyone would be like that all the time. What you need to do is come up with a reason why your character would choose to live like that.
However, it is a little bit more complicate than simply inventing a plausible reason for their behaviour. You need to climb inside your character’s mind and try to experience life from their point of view – this can be difficult and exhausting.
No one thinks, “How can I be mean to that person today?” or “How would I act if I were a really mean person?” Everyone, and I mean even the sickest, most depressed, unworthy scum of the earth, believes they are the hero of their own story. Everyone believes they are in the right and what they are doing is best/right/necessary/most helpful – because that is human nature. We are all capable of justifying even the most depraved behaviour to ourselves, because we believe either it is in someone else’s best interest, for the good of all, necessary, or just ‘right’.
Often, mean people don’t enjoy what they are doing, they may even resent having to do what they do, but they see themselves as having to bear the burden of society, taking on the responsibility, or having no other choice, because no one else will do what is necessary. Somehow, they see their actions/attitudes as redeemed by their sacrifice/suffering on behalf of others/society/’the greater good’.
Your job as a writer, is to get inside the mind of your character and discover how and why they think they are the hero of their own story. How come they believe what they are doing/the way they are, is benefiting others. Once you discover how they justify themselves within their own mind, they will become relateable to you and to your readers.
So have some fun developing an awesomely mean character who is nothing like you.