Jeanne d'Arc Alter had come far too easily, to the point that Su Yun felt all the arguments and tricks he had prepared had no chance to be used.
She was just too easy to win over.
He was genuinely starting to feel guilty.
Still, having come this far, he had no intention of stopping midway. It was simply that Jeanne d'Arc Alter had been too easy to win over—so easy she may as well have handed herself over—that most of the lines he had prepared for what came next were completely unnecessary.
Afterward, Su Yun naturally said that he had no desire to be enemies with Jeanne d'Arc Alter, but he also did not want to see her harming people as part of the Mystery side. He was conflicted, yet he made it clear that he would not bring anyone to hurt her, and told Jeanne d'Arc Alter to hide herself well and not let herself be discovered.
He also said that over the time he had spent with Jeanne d'Arc Alter, he had come to know that she was a good girl, not someone born evil. The wrong she had done in the past must have been due to the Mystery side instilling her with misguided thoughts and actions when she had been created as a special Mystery.
That was, the time she had killed someone under the Mystery side's control. After that, he had never seen Jeanne d'Arc Alter kill again. She had not even gone out to cause trouble, instead staying home every day and surfing the internet.
How could a Jeanne d'Arc Alter like that possibly be a bad girl?
In any case, it was the standard declaration of an overly kind guy, with the exact image being those anime romance scenes paired with BGM.