Master and slave is a relationship, you can't have 1 without the other. The people being manipulated by the psychopaths are an as much of a problem as the ones pulling their strings.

Both parties share a moral culpability to resolve the issue as one could not exist without the other.

I would disagree about calling it evil, as expressions of duality are not interpreted the same by many cultures and referring to psychopathic behavior as evil would just dilute the dialogue to the baseness soul unable to hold a significant meaning to people as they engage in the extremely complex nature of the Hegelian Dialect.

Deception or deceit could potentially define the role the psychopath is playing, but thats only 50% of the equation.