Narcissism is far more common because it's how shysters are able to justify the crappy things they do. They feel entitled to what they can scam away from others because they feel they deserve it more than the victims. This warped thinking allows them to take sympathy out of the equation.
But it also helps you to spot the con artist. Be aware when you're talking to someone who has an inflated sense of importance about themselves or their topic and who is showing little empathy and poor listening skills. Another tell is if they're too aggressive in expecting compliance to their wishes.
Con artists are professional storytellers. Whether it's Anna Sorokin, known as "the Soho Grifter," who, posing as a German heiress, duped hipsters out of $275,000, or Elizabeth Holmes, who spun diabolical yarns about an entire company's premise (Theranos), this is what con artists do. The best tell an emotional story that transmits elements of what the listener already believes or wants to believe.
If someone claims to be Satoshi always apply common sense. Scammers and con artists are great story tellers. Don't trust their stories - verify!