I mean... it make sense to me.
If your altering parts of a person's desirebase to make them want the things that are useful to you (to protect the world, ect) then... why not make them want to sleep with you?
You already started the mind-control, the sin is done. You might as well get the bang for your buck. Besides, the new version won't mind at all, will she?
S'like, if you're going to strap someone down and harvest their bone-marrow, why not take a little blood too, while you're at it? You already made the incision.
Clearly you've already decided that morality isn't a concern here, so why be squeamish?
Emotion-control is even fuckier than mind-control though.
You're not creating a surface-layer alternate self who can suppress the real self and puppet the body for you. You're actually editing and saving over their core personality in an irreversible way.
Once those new priorities have been baked in, this is "The real them" now.
It's the only one left.
The choices they make aren't things they're being compelled to do by shaky mental programming.
We all make decisions based on the things we value highest. If those core values are altered, then our new desires will give rise to new decisions.
TLDR: If you mind-control someone into sleeping with you, it's rape by coercion.
If you alter someone's desires to the point where they want to sleep with you, doesn't that mean that you have consent? Because the decision to sleep with you is a natural response to their core desires, rather than something you delibirately programmed them to do?
Sure, the altering of the desire-base was still mindrape (or murder, if you believe that you're erasing a whole person and creating a new one*) but everything after that is their own discussion.
So the sin you bear is that of mind-controlling people (which he was already doing anyway) and not rape (which he believes himself to be innocent of)
It's twisty as hell, but it sorta checks out.
Especially if it's irreversible.
If a person insists that they want something and it's impossible to change them back to not wanting it, then do you have the right to say that they're not capable of making their own decisions anymore? Presumably for the rest of their life?
Not letting your teammate sleep with the mind-controlling badguy is one thing, but who knows how much her desires were altered. Can she not consent to sleep with anyone, because her tastes are diffrent from her original self so it'd be rape even if she wanted it?
Can she sign something at the bank, or write her own will, or is that not allowed anymore?
You wanna treat them as incurably insane and say that they're not allowed to make any kind of decision anymore because their priorities aren't the same as they were before?
Mind-control morals are fascinating.
Like, what if there was a gun that turned you reversed your sexuality? It doesn't do anything else or program you to like anyone specifically, but being gay (or straight, if you were previously gay) is now a part of who you are.
So you find someone and decide that you want to sleep with them, can you consent?
Old-You wouldn't have, because Old-You wasn't (or was) gay, but Old-You isn't here and New-You wants Sausage (or Tacos)
Is New You just never allowed to have sex or express attraction to anyone ever again?
*Personally I disagree on this point. Evil-Paul mentioned that Ollie has a lot of his prior character and personality, which says to me that the proccess used to alter him (and presumably everyone else) went "Open File, Edit File, Overwrite."
It's the same person, but they were changed.
The actual Murder-And-Replace plot would be "Delete File, Create New File."
There would be no carry-over between the old person and the new one, and they'd probably be completely unrecognisable.
The latter is also probably much harder because building a whole mind and personality from the ground up sounds really complicated.
Point, Correcting.