I Taught the Villain to Become Obsessed with Her Senior Sister

Blurb: Lan Shanjun transmigrated into a book. The unscrupulous author left the story unfinished, the villain remained consumed by demonic nature, and the protagonists both died. By the end, the villain had killed everyone, leaving only herself alive and breathing. By a stroke of bad luck, Lan Shanjun became the villain's senior sister, a cannon-fodder character who was the first to get killed by her. "..." Luckily, she had arrived early in the story. To avoid her cannon-fodder fate and help the protagonists reach their happy ending, Lan Shanjun decided to deal with the villain first! Strike while she's weak and kill her! But when little Cang Wu was brought before her, the dainty, adorable girl tugged at her sleeve and called timidly, "Senior Sister." Oh! Just listen to that voice. It could melt anyone's heart. Lan Shanjun's eyes practically bubbled with delight. How could this be the murderous villain from the book? She was clearly a sweet little girl, her adorable, soft-spoken junior sister of the future. Lan Shanjun took it upon herself to reform the villain, and taught her so well that the girl became obedient and adorable, and utterly devoted to her senior sister. At first, Lan Shanjun thought the villain had become a good child because she herself had been gentle and understanding, giving her care and love. But the truth was that... She had one of the dragon eggs Cang Wu had lost. She couldn't return the egg. So could she at least benefit from having it? Cang Wu was forced to stay by Lan Shanjun's side in the form of a child. Her disguise was flawless: her obedience was fake, and so was her kind heart. Where Lan Shanjun couldn't see, Cang Wu stood tall and proud, looking down on all things. She stomped the head of a loose-tongued cultivator into the mud. Born with a noble bloodline, she had every right to disdain everyone. The only person Cang Wu would lift her chin to look up at was her. Cang Wu awoke because of her soft murmur, and from then on, she was destined to follow her for the rest of her life. The bond between senior and junior sisters grew deeper. Then the protagonists appeared, and Lan Shanjun, desperate to avoid a tragic ending, focused entirely on the plot and ignored the gaze that followed her day and night. Later, Lan Shanjun was trapped in a place where no one else lived. The one who imprisoned her was Cang Wu. The obedient, well-behaved junior sister she remembered cast off every disguise, revealing an extreme madness in her eyes. Cang Wu bent down and bit the side of the woman's neck. Scales appeared faintly around her eyes, revealing her monstrous form. Her tail coiled around Lan Shanjun again and again, as she greedily and contentedly marked her from head to toe with her scent. "Senior Sister, you can only look at me." Please note: 1. One of the female leads is a little Azure Dragon, and a true senior-sister devotee. There are eggs in the story, but no hatchlings. 2. The worldbuilding is entirely original. Cultivation levels: Spirit Awakening, Consciousness Gathering, Golden Core, Life and Death, Soul Illumination, Grand Void, Return to the Ruins Immortal Realm. 3. This is not a power fantasy. The female lead goes through a process of growth. Theme: The spring breeze knows my heart; like a dream, it eases longing.