Suggest me a thriller where the main character is mentally unwell and/or an arguably bad person, similar to Boy Parts, American Psycho, You, and Fight Club

I’m not a big fan of murder mysteries but if it’s really something that fits then bill then totally cool. I tried to like Exquisite tve Corpse but I didn’t like the writhing style that much. I’ve already read Gone Girl and Sharp Objects

by un_gaslightable