Field Programmable Sister Wife
It turns out that some extremely toxic narcissistic people, who are, what we should probably really be calling "sociopaths" have a meme installed that allows them to deeply influence the behavior and "programming" of their "sources" (familiars or is that just vampires?)
They can for example marry a naive, simple woman and begin literally reconstructing how that persons sees reality. Like a brain slug, or a virus, or a cordycep!
By age N, woman is completely hopeless. She hates the Free Masons, and thinks the armenians are "good family people" or...whatever random mapping of opinions has been burned in.