I may be biased about this but I still think that a very small amount of love is mixed in with Jack’s feelings for Lacie. My reasoning is that, at the very least, at their very first meeting, I think we can agree he felt positively toward her, right? Past there, as he became warped, confused about his own feelings, etc., is when it became a sort of hate. But I think it was described as a hate born from the fact that he did like her, that she had such an impact on his life. I’m pretty positive that if he can get through his identity problems, his ‘true’ feelings will be affection for Oswald, Alice, Gilbert, Vincent, and also, Lacie. Not only does it fit how I’m pretty sure his character is, but I think it fits how Pandora Hearts has been in general. In its present state, obviously it is not a healthy love, but I find it hard to believe that there is no love at all anywhere in him for her.
It’s just twisted up in an obsessive, vulnerable, desperate, helplessly selfish, very confused mixture of other feelings/nonfeelings.