Malignant narcissism is recognized by psychologists as a blend of two dangerous pathologies—Narcissistic Personality Disorder (NPD) & Antisocial Personality Disorder (ASPD).

“So much for Caligula as emperor; we must now tell of his career as a monster.”
—Suetonius
https://www.mind-war.com/p/mathematics-of-caligula-malignant