A perfect insult is one which appeals to ones insecurities, what they don’t want to believe about themselves, but fear is true. By insulting someone in this way, they may become dependent on you emotionally, they may rely on you to revoke the insult and ensure them that what they said is not what they really see or think, thereby putting them at ease.
Similarly, a perfect compliment is one which too appeals to ones insecurities, what they want to believe about themselves, but fear is untrue.
One can nearly as easily be ensnared by a perfect complimentor, as by a perfect insulter, but the most dangerous seducer of all is the one who is both able to shatter some tentative aspects of our imagined self image, and affirm other tentative aspects. In this way they are able to appear to be completely genuine in their commentary about you and are not clearly either the archetype of the abuser(one who manipulates through insulting) nor of the charmer(one who manipulates through complimenting). So clever is one who is able to do this, that they are literally indistinguishable from a friend and their insulting or charming comments can only be concluded to be down to their honest opinions, to any outside observer. No behavior can identity this type of manipulator.