She used innate skill which drained her life force in order to protect Su Xing from Li Taisui.
She had sexual intercourse with Su Xing while they were both unconscious under the effect of aphrodisiac. Su Xing wanted to take responsibilty after his rape like action but Shi Xiuxiu acted like nothing happpened. While she was recupeating from her injuries with An Suwen, she heard what Su Xing's Star General's think about him and she was very impressed. Before her true spirit dissipated, she promised Su Xing if they meet again in the Star World, she will be his woman.