EDIT: I think I just discovered true hard mode. Finally started my first rampancy run and...let's just say it is going FAR better than expected. I have a double rampancy, which is going better than expected even with starting the final battle early to test out current final battle conditions. I expected to fail several times.
I haven't done an aversion distortion yet, but from what I've read, and what I assumed from their forsaken traits, they basically have split personalities or something. Like Jekyll and Hyde.
From my experience it's less about reason and more about them just falling in love with you via Stockholm syndrome. I've done 2 negotiations so far.
One of them was "fully aware of her feelings for the demon lord" during the final fight intro, surrenders cause "I can redeem him, even if it means falling myself" and then just goes super happy about being your lover since "we are like husband and wife!".
Second one literally was welcoming me to her room during meetings wearing sexy lingerie, invited me on a date to amusement park because "her time with you is the only time she is truly happy and free from the horrors of war nowadays".
It's basically "can love bloom on the battlefield" meme.
That actually kind of makes sense. In the victory, they don't seem very enthusiastic, but are immediately more than willing at least in their wording when talking to you. This could be the Hyde personality coming out while the Jekyll personality, their normal self, goes permanently dormant, only peeking out slightly when you try to train them in something that needs their cooperation with too little obedience. Full obedience, or unthinkingly obeys as the game puts it, could stand for the Hyde personality taking over permanently.
Stockholm syndrome also makes sense in negotiation, perhaps their mind is seeing the reasoning as an escape from the trauma they are put through daily during the loop and so they agree with you in the end when you appeal to this falsified logic in their heads. To be honest, my current Chosen team is completely unsuited for a triple negotiation as my Vassal is ineligible right out of the gate and the other two it tells me to inseminate or sodomize (both moves I am avoiding), so I stopped my negotiation run short of getting any Chosen to come to the back alley.
I did do a temptation run and, during one tempt, the tempted Chosen willingly took thralls in the ass, so that one is risky for my total virgin goal since they could open their legs at any time and I would have no way to stop them from being penetrated since the action is non-interactive after starting it. It also seems hard to get a triple win on, which is why I have a double temptation win with a normally beaten Vassal.
I have never tried rampancy, seems a bit tough to pull off with the requirement of a 15 turn surround while their HATE is higher than their INJU. It also requires inseminate, which goes against my goal, and innocence seems to be the one vulnerability most often broken twice automatically by a capture. My Vassal is also ineligible because of a T2 pre-break in confidence. I may just try this for fun to see if I can get Fury, the most probable Chosen of the three to get violent, to go rampant.
When an Aversion chosen lose they modify their personality into one more fitted for their survival. Actually, if you talk to them they'll say they're not the person you fought but just someone who have the same name and body as them, and that said died when they lost
So a personality split, the more willing to serve personality taking control. I have a Rebel that used this line, a Vassal that says he is nothing like the weakling that lost, and a Fury who says she would love a new name she does not share with the Fury that lost. No wonder the weak-willed, mousy Vassal went complete sadistic psycho. Also, the mental image of a tough girl character like Fury curtsying on stage is freaking hilarious.