Invented Personas to Manipulate Others
Psychopaths are a different version of themselves for every person they interact with. They also have 'group personas' for family, organisational and workplace interaction.
Highly Unreliable/Broken Promises
Psychopaths will make the most incredibly ambitious plans including you as their right hand man or woman, then, on a whim, discard those plans and move on to some other crusade that excludes you. Targets often alter their own life plans to help the psychopath reach their imaginary goals, resulting in appalling emotional, psychological and financial chaos for the victims when the psychopath moves on.
Idealisation Followed by Cold Rejection
At the height of their idealisation of you, the psychopath will show you obsessive 'love,' care and attention. However, once they feel they have you where they want you - or the relationship has ended - if you collapsed in front of them on the street they would simply step over you as if they'd never met you and continue on their way. Outrageous smear campaigns against the discarded targets to falsely portray them as psychologically unstable, self-serving liars or abusers are often undertaken by psychopaths following the ending of a relationship.
Becomes Obsessed with a Hobby, Cause, or Individual and then Loses Interest Instantly
However, as soon as the relationship is established, the downward trajectory from idealisation of their targets and towards the inevitable devaluation and discarding begins in earnest. It may take weeks. It may take months. It often takes years. Nevertheless the psychopath always begins the devaluing of their victims as soon as the relationship is legitimised and is always on the lookout for an 'upgrade'.
Phony Altruism
Buys into either secular and non-secular belief systems to appear superior or enlightened. Will align themselves with 'morally popular' causes to make themselves appear enlightened and with a sense of deep moral wisdom and compassion. But it is always a pose; the psychopath's association with these causes is a veneer to fool others into trusting them. It's always fake; always an agenda.
There is Nothing Real Behind the Persona
Behind the months or years of perfectly-constructed performance by your psychopath is a nothing: a void, a blank, a hunger for something the psychopathic entity can never define. They now see no further benefit in playing this part and have moved on to a new role. It is just business. You are treated to a completely new, cold and emotionless persona. "Who is this stranger?" you will ask yourself over and over again. It is so bewildering.
The Sudden Goodbye
Then the psychopath finds an upgrade, changes their persona, will often change their look, fashions and even change the subject when they suspect others are figuring them out and you begin asking questions. "Hey, never mind that, it is lovely weather we are having!" Stated in a chipper and almost giddy manner (with an obvious underlying glibness). They are repressing the internal excitement at having pulled a fast one on you.
The psychopath is literally filled with an adrenalin rush which lights up their whole facial expression with a gigantic self-satisfied grin - while the people the psychopath has stabbed in the back are expected to "get a life FFS..."
The psychopath then mocks, ridicules and back stabs the people whom they "loved" only days prior and are now left in a state of chaos and confusion. Along with more glib statements as if "everything is OK". Then the psychopath generally goes into hiding for a short while from their victims and emerges with a new life, relationship, in another country/region in a completely whole new persona and a new mask of manipulation and social sanity. This was the new persona which the psychopath had been clandestinely crafting behind the scenes.
It is essentially an internal psychotic rampage hidden behind platitudes of "time to move on" and other superficial pontifications to hide that this is a completely deranged predator working their new "target" while dehumanising and discarding the ones whom they have no further requirement for. This is what leaves people in such shock - until they start to realise what they were in fact dealing with all along. A psychopath.
Then your hero, social activist, revolutionary, celebrity, cult-of-personality hero (persona) moves on as if the previous persona never existed - but it is always their undoing as they assume they are smarter than the people whom they have manipulated and fooled into their cult-of-personality. Which is why they always insult and mock the ones who supported, championed and loved them as the psychopath walks away. This is always their fatal flaw. Their testosterone-charged impulsive self destruct button. They get cocky and their God Complex goes into overdrive and everyone sees it for what it is. Endgame.
But there is much more to understand!
And that is, basically, how the psychopath exerts his "power."
He cannot do it without the assistance of more powerful beings who are still willing to act.
Many of those beings are quite off the deep end themselves, but not to the degree that the psychopath is.
The strategy, then, is to deprive the psychopaths of their slightly saner helpers. And that means getting the helpers educated regarding the situation they are in, and how to successfully disconnect.
Done well, this can stop a war dead in its tracks. All you have to do is get both warring parties to discover the third party that has been inciting the conflict. With that person's (or group's) lies and inflammatory actions exposed, the actual conflict becomes manageable.