>>281669084
It's not easy to pull off. Many Japanese fans will complain when/if the protagonist starts going purely psychopathic. It takes a truly uncaring author to ignore them and do as he likes.
Seriously, I was surprised to learn how many campaigns were initiated to try and undermine Overlord back when it was airing.

"He's a psychopath!"
"Only maniacs read this!"
"What sort of sick animal enjoys this?"
Maruyama didn't care.
Kill and wipe out everyone in the glorious name of Nazarick.