Starting with The Blood of Youth, I Became the Protagonist's Little Sister

Wen Youliang was once a wandering spirit. After binding with a cross-dressing System, he must travel to different worlds and become the "little sister" of each world's chosen one. I'll add some original elements of my own, such as demons and ghosts. Each world has a different ending, some good and some bad. First world: The Blood of Youth. He is Qu Fanyin, Princess Jinzhao, and Xiao Chuhe's missing younger sister, Xiao Yuxing. Second world: The Untamed. He is Qu Fanyin, and Wei Wuxian's younger sister, Wei Xuanxuan, who was separated from him as a child. Third world: Word of Honor. He is Qu Fanyin, and Qin Jiuxiao's younger sister, who went missing, as well as Zhou Zishu's junior sister, Qin Shiyue. Fourth world: Douluo Dalu. He is Qu Fanyin, Qing'er, the only surviving blood relative of Light Feather Douluo. Fifth world: Mysterious Lotus Casebook. He is Qu Fanyin, Li Lianhua's missing younger sister, Li Xiangyue.