Gu Xijiu once tried very hard to be immortal. Unfortunately, it was all just a dream now. She chose to die with Mo Zhao, to get revenge for her friends, and to kill a devil for the world. She had certainly proved her capabilities as well.
Subconsciously, she wanted to prove her abilities in front of Di Fuyi. She wanted to show him that she was not that bad compared to Lan Jingke. Why could he not try just to love her? Unfortunately, she did not bring it up even until the end because she felt that it was not true love if she had to beg for it.
Since he only loved Lan Jingke from the beginning until the end, she would return Lan Jingke to him. She would fulfill his wish and her wish as well.
'Di Fuyi, I wish we will never see each other again; even in our next life.' But, there was no next life for her anymore. She would disappear as her souls had to pay the price for forming that array.