Jiang Yi did not rescue Tang Yan and Tang Xue because he wanted to own them. Still, after discovering that they probably had astral bodies, he was quite surprised.
Instead of saying that he was being kindhearted, it was more accurate to say that he was having a great internal struggle.
In all these years, his hands had become covered with blood. He had killed many people. Although he never once killed a civilian, some killings he committed were unnecessary. He felt like he had become quite numb to the entire process. Now, he was not even sure he still knew who he was. He wanted to look inside himself and try to find some sense of humanity.
After gifting a rose, the hand would have lingering fragrance!