Despite his past sweet & caring personality, Damien has always been perceived as a bad guy because of how "scary" his appearance looks. He eventually just...got tired of trying to be nice to others when all they did was spread rumors about him in return. The fear mongering got to such a point that he just said screw it! and decided if people were going to be terrified of him then he will be terrifying. Now he's more or less,, a giant asshole.