The gas lighting behavior comes from a person who has some sort of severe personality disorder. Probably Sociopath or Psychopath.
I unfortunately knew someone that had eerily similar behavior–gas lighting, extremely manipulative, vindictive, creating clouds of doubt everywhere, pitting people against each other…while at random times could appear to be quite amiable. After knowing them for 10 years, I realized they were irredeemable.
Their darkness and deceit and indifference to decency and the truth ran very deep. To their core. I didn’t want to believe that there are people out there that are that disconnected from human compassion. Donald Trump is such a person.
There is nothing but darkness in there.