You nailed it. I have seen the same pattern before. The dad is feeding this fire to destroy the mom. Real sad.
In the case I observed if the functional adult leaves or divorces the dysfunctional one the dysfunctional one will dedicate their whole energy in life to get “revenge” on the functional parent and will manipulate the children into hatred of the functional adult.
Destroying the children becomes a goal, to generate grief for the loving parent.
It is psychopathology in action.
Her husband is a real piece of work.
Lived through it. The gaslighting and extrusion and marginalization were breathtaking. The two that were manipulated and manipulating are long gone. The manipulating ex continues to work his sociopathic ways