Ok i wanted to make this post because i was raging and beating myself up about this girl i was dating. I was blinded by her "attractiveness" that i didn't realize who she was a person. I just wanted to post some tips to help others realize if they are chasing after or dating a narcissist. Narcissists are really good at turning you into feelings of "oneitis" for them as well.
No Empathy - If the guy/girl you are dating or pursuing has no emotional empathy that's a big warning sign. No emotional empathy means the inability to step into another persons shoes and lacking intuition. Some signs of no empathy include doing things such as blowing you off and not giving you an apology or reason, taking no interest in your feelings, doesn't ask you questions about your day/self. Sometimes narcissist will make plans with you just to blow you off later intentionally.
Cold shoulder - Narcissists will also ditch you or leave you behind in a heartbeat if you don't do what they want to do. They won't compromise with you on anything, and it's what they want regardless of your desires. If they get the chance to ditch you for "better" plans they will do it and not feel the least bit of remorse.
Treats others badly - Talks about friends in a negative light, gossips frequently. Tries to downplay others achievements including your own. Takes no interest in your achievements unless they involve themselves. Only thinks about what they can get from you instead of what they can provide in a equal relationship. Aka, i'll hang out with this guy only because he will buy me drinks. I will only hang out with this guy because he gives me attention, and so on.
So to sum it up, if you notice these traits id say run the other way fast as possible.