What gets me is that XLH does have every piece of information to selflessly kill herself with the Chengying sword:
- she knows that DFQC wants to free the 100,000 soldiers in the Xuanxu realm because he promised so - if she kills herself, the soldiers will be freed, - she knows that DFQC doesn't control Hellfire anymore which makes him weaker - if she kills herself, he won't need Hellfire anyway, - she knows that DFQC needs to find a way how to protect his people because the war is coming - if she kills herself, the war will probably stop or the scales will turn, - she knows that the primordial spirit of the Chidi woman is inside the Bone Orchid, feeding on her and gradually killing her - if she kills herself, the spirit will be freed, - she knows that DFQC made a pact with the evil spirit which is extremely dangerous - if she kills herself, he won't need it anymore.
And that's why she did it. Not only she freed him of the Heart Curse she inadvertently casted but she freed the 100,000 soldiers and saved his life from the evil spirit because colluding with it would lead to his untimely death. She wants him to live even when she can't be with him (for obvious reasons).
She, however, doesn't understand one thing: - why did he claim that he never loved her and that he just played tricks on her. She obviously doesn't believe it and evidently, she never will. And even if she eventually did believe it, it was never a reason for her to stop loving him.
And then we get the scene on the bridge in the Cangyan Sea where DFQC: - comes up with the best kind of love confession he ever could, - explains that the only way to break the Bone Orchid and save her was to stop her from loving him and that's why he lied to her and humiliated her, - thus doing basically what his father did and what she is doing at the moment.
I just... the way the realization hits her like a ton of bricks is so well told. You can see that she was already fragile and that's why she told him to stop talking. And then, he just blurts this out and it's just too much for her, too much for the mask she willingly wears. And she breaks. And it's heartbreaking, twisted, angsty and beautiful in the same time.
Wow.
