I find that consent is a red herring.
An interesting question that came up for me when I was thinking about all this some years ago was whether or not a person can consent to being punched in the face or some other terrible experience. Are there some things that are wrong even if the victim agrees to them? Like agreeing to be eaten by a cannibal? I think society has decided to draw lines (e.g., cannibalism) for many things which render consent inconsequential. And that is interesting.
Further, consent cannot be valid if the subject is unaware of what they are in for, and especially when they are being groomed. An abusive relationship, or cult, for instance. Which brings me to questions about when does persuasion cross the line into grooming and unethical territory? It is always unethical if the person is being persuaded into something they don't want or wouldn't want.
I think both above paragraphs relate to this concept of whether consent is distinct from the question of morality and ethical behavior on the part of the would be perpetrator. It seems to me that if what the person is doing to the other person is wrong, then consent is a tired topic often employed in defense of the perpetrator to distract from the wrongness of their actions ("but they consented!"). If what the person was doing was antisocial (evil) then consent is irrelevant.
The problem I keep coming back to is that we need to decide as a society what is unacceptable behavior and enforce it. But it's not even that simple because people want to get away with evil stuff and don't want the rules to be too strong. Those people distract us and mix up our minds and derail our focus on them and their bad behaviors by making us blame ourselves, question our consent, and other red herrings. I've come to the conclusion that consent is often a red herring in these arguments. It's not the thing to focus on if we want to solve the problem of evil. The question to ask is whether what the alleged perp did was simply awful, dark, sick, twisted, wrong.
Is starting a new age cult in which you brand women and emotionally manipulate them and use them for sex wrong? Heck, is simply branding women wrong? Can women consent to being branded and if they do does it even matter, or is darkness just darkness and consent inconsequential?
This might not make sense to others. It's kind of hard to articulate but I hope it comes through!