I have been thinking for days about this but like episodes 10 and 11 of Trigun Stampede-- specifically relating to the twins-- is such a fantastic representation of both rape and familial abuse.
Vash is an unwilling participant in Knives' goal to make many independents, and while the individual plants have no discernable will of their own, Vash does. Vash is being utilized as the conduit for Knives to impregnate hundreds of plants, all without Vash's consent. In lieu of the actual hosts being capable of giving or rescinding that consent, it falls to Vash, and Knives happily and willfully removes Vash's ability to say no. He strips Vash down to his components and uses only that what benefits him most.
And worse than that is how he attempts to usurp Rem, the most important memory in Vash's life. He doesn't only attempt to remove the memory, he seeks to corrupt it and to push this idea that no, actually, it was him. He'd always been there for Vash. He'd always been the one Vash turned to.
There's this insidiousness to some types of abuse. The kinds that turn your perception in a circle like a cartoon, uncertain of your direction and suddenly so very afraid of moving forward. That insidiousness is so often met with "is this really abuse?"
And I think that Knives and Vash hit a specific type of abuse that is familiar to me. Another post I saw compared it to being a transman, and I agree. You become both too coarse and far too soft, in the eyes of the abuser. You become unacceptable except in the manner by which they have decided you can be loved. You become the component parts, and your use and faculty is determined only by what the abuser wants of you.