Psychopathy:

via Rob Henderson:

"Some of the psychodynamics of the psychopath bring us closer to what we see as their evil, or their wish to destroy goodness. Psychopaths are aggressively narcissistic, and this aspect of their character pathology is often expressed behaviorally by the repetitive devaluation of others ... Psychopaths generally do this for two reasons: first, to maintain grandiosity, or their sense of being larger than life, and second, to repair perceived insults or emotional wounds ... The repetitive devaluation of others, whci may range vom verbal insults to ..., also serves to diminish envy .... Envy is the wish to possess the "goodness" perceived in others. If the 'good object' cannot be possessed, it must be destroyed or damaged until it is not worth having."