here's my take on it....
Take a guy, remove physical stuff (unless you're into transvestites :Q)
Add manipulation skills
Add the ability to lie at any instant of any day
Add the ability to show fake compassion
Add the abbility to say one thing, mean another, and assume yet another, and then go do something totally random.
Add the "innocent" factor (see manipulation)
that's all I can think of so far... any more?