I recognize what is being described with in the behaviour, @whumpthereitis from an experience of my own.
A highly manipulative individual, but also quite self-deceiving and unable to shake the idea that I was bad, malicious and wrong, even with documentary proof.
He had got the wrong end of the stick in a particular business meeting - which fair enough, wasn't entirely his fault. A different person had been a little unclear, and was supposed to outline specific terms to him, but didn't.
However, he latched onto me as the one responsible for a scenario that didn't even exist. He harassed, plotted and pursued me based on that misconception. Even when it was conclusively proven that I had never planned or intended for the scenario he imagined, he was too emotionally attached to his plan of destruction to drop it. And he had whipped up staff in his own business to hate me too - quite disturbing, really.
A logical reaction to seeing clear cut proof of my intentions would have been to stop, not to double down.
Funnily enough, long before this he had mentioned the emotional reactions of other members of staff, and I had joked, "sure, whilst I am cold and emotionless like a snake" - and he agreed! He found my impartiality and professionalism cold, and identified a lot with the more emotional reactions - in spite of considering himself good, worthy and logical.