@ninjakai03 It's from him realizing how much shit he's put her through for his own selfishness while being ignorant of her circumstances. His hate started from the idea that she was replacing his lost sister, and that she wished for her to never return. He believed she tricked his father. However, because of what she said this chapter he now realizes that 1) his father basically kidnapped her(that is, she either went with him or starved to death. No other choices.) 2) She was afraid of going back to such an uncertain, painful life when she was young and made that initial wish, 3) she didn't even know the value of a necklace, let alone money, and thus she didn't come there out of greed or a desire for power, and 4) that he made her life such shit that eventually the idea of going back to being a beggar was better than staying in that hell hole that he calls "home." Simply put, he now realizes that she wasn't a bad person in the beginning(and realizes that she probably currently isn't a bad person), and that all of her actions thus far is be because of him and his family. Every tantrum, every outburst, every time she's tried to escape, even her skinny, malnourished health; all of it is because of him and his family. He realizes that he did horrible shit to an ignorant 12 year old girl who didn't know better and had nowhere else to go and now thinks favorably of her because he realizes what he did was wrong. That
he has been in the wrong this entire time.
With all this taken into consideration then it's no wonder it went up. He feels sorry for all the shit he's done to her and all that happened because of his initial actions. He
feels sympathy for her and regret for his actions.