actually his hate towards Athy is just on the surface the first and current life of Athy is just the same. Even tho Claude feels hate he still feels for Athy as she is his and Diana's daughter. It's just that Athy did something different in her current life that's why the timeline changed. So I'm thinking that in the original Lovely Princess Novel there's a whole another reason why it ended on Claude killing Athy. ╮( ̄▽ ̄)╭
man I'm in love with this, it's so beautiful and i love the story, i cry a lot because of a lot of things, and i never cry until now because of a webtoon, man i like every character, lucas, ezekiel (i think that's his name), jeannete, the maid's, athy, everyone and even claude. i think that's a good reason why he killed athy in the first story, he suffer so much because of her mother, and he try to erase every memory of her, and seeing (i hope that's the right word) athy makes he suffer even more, so when he gets the chance to kill her (because she "poison" jeannete) he don't think twice, I'm not saying that what he do was right, but I'm trying to understand, because I'm liking him now and in the first story he isn't close to athy, so of course he would kill her without remorse. (if i wrote something wrong sorry, I'm not using google translation)