Becoming (2020) on Netflix

Plot summary

Lisa Corrigan and Alex Ferri have just gotten engaged and set off on a road trip across the United States. Somewhere along the way they cross paths with a malevolent force that predates the country itself, one that has left murdered families behind it for hundreds of years. It settles on Alex and starts to take him over, a little at a time, altering the way he writes and carries himself. Lisa watches the man she agreed to marry turn into a stranger and wonders whether he has fallen out of love with her or whether something worse is happening to him. Kevin Lee, a survivor the force left damaged, has spent his life fighting it.