Please explain to me, Joker's Feeling towards ZiXia [spoiler]

It's poorly done but basically Joker/Monkey King was fated to fall in love with ZiXia and had fallen in love with her to begin with and his longing for her was pretty much the catalyst of the whole two movies.

Only his poor life choices led to Jing Jing so in an ironic sort of twist, Jing Jing was the rebound girl even though in the first movie, Joker was painted as the reincarnated rebound guy.

It was only because Joker/Monkey King would not have chosen to go back and recover his memory and relearn his mistakes if not for Jing Jing's death that he was never reintroduced to ZiXia until he used the Pandora's Box. However if Joker had simply recovered his memory then and not desired to go back to Jing Jing, Joker would not have learned his lesson and be put into a perspective where he would reject ZiXia.

Basically the entire lesson of the story (if there was one) is that the Monkey King by his stubborness had chosen the path of most suffering. The route he took basically meant that the woman in terms of ranking he least loved would in turn show him to the way to the woman he loved above her and the cycle would continue until the second woman he most loved would spell it out to him that he did not treasure the women he loved the most and in a sort of circular cycle, Jing Jing found that out because Joker's heart who yearns for ZiXia had yearned towards Jing Jing which in turn made ZiXia cry which in turn is what hinted to Jing Jing that Joker loved ZiXia more without anyone really being told why one person loved the other except for the subconscious honesty of Joker's heart.

In the end though, the most important key was that the woman the Monkey King loved most would be the one to have made the Monkey King be the hero which is sort of unfortunate as there was no way to do that until it was too late to save her life and the Monkey King sort of have himself to blame both for playing with people's hearts and also for rejecting an important quest by using a woman he didn't love just to sacrifice the Longevity Monk. It's sort of like paying for all your karma in one life instead of multiple lives so the result was that Joker had to fall in love with several people and then suffer because of them but at least instead of living with tears of sorrow, he sort of saw his loved one ZiXia die while being happy.