The best possible scenario:

Wanda and Vision have retained most of their personalities and control except specifically when it comes to HYDRA. Vision is unable to fully articulate thoughts that are subversive to HYDRA; Wanda is unable to act on thoughts that are subversive. Otherwise they are aware and the affair they have started is to comfort each other.

This is not ideal, but we can’t change it and at least it’s a scenario where they can be said to each be consenting to the relationship.

The worst possible scenario:

Wanda and Vision are both unable to say no, and Chthon is getting a kick out of torturing them.

No, wait, that’s not the worst–the worst is one of them can’t say no, and the other is taking advantage. That one is the worst.

Please, please, please Marvel–I know I’ve said that you should always fear them getting back together because of the inevitable break-up, but I didn’t realize that you could make me fear the hook-up even more and now I understand I underestimated your awful power so please don’t do this.