Narcissists are some of the most arrogant, egotistical, and vane human beings that you could ever meet on the planet. The story goes that Narcissus was a very stunning person with his looks, charm, as well as his own admiration for himself.
He was so in love with himself that he attracted the ire of a goddess claimed to be Nemesis, goddess of vengeance against beings who were consumed by their own arrogance.
Essentially, she made him fall in love with a reflection of his own image until he died from staring at himself for his entire life.
These kinds of people have a very cruel intent when it comes to being social with others. They often times find ways to make people appreciate their beauty and charm enough for them to manipulate you at every single turn they can get.