He Stole His Older Brother's Love Interest

After divorcing Xie Zhizhu, a powerful figure in the cultivation world, Shen Yan became a female demon hated and hunted by everyone. Her ex-husband, Xie Zhizhu, was as radiant as the moon and exceptionally gifted. His only flaw was having been her cultivation partner for three hundred years. Before the wedding, many people warned Xie Zhizhu that the blood of the demonic sect flowed through her veins and she should be eliminated as soon as possible. Xie Zhizhu staked his life and bound his soul by oath, swearing to protect her for all eternity. Shen Yan had believed him once. But when she was forced into the demonic path and left without a single ally, Xie Zhizhu never came. Instead, she received a letter from him severing their bond and ending their marriage. After being reborn, she became a low-level rogue cultivator with little magical power, and a contract partner who was on the verge of dying of illness appeared at her side. This partner looked exactly like her ex-husband's younger brother. Shen Yan thought Xie Zhilin had come on his brother's behalf to eliminate her once and for all. But when she was poisoned by an aphrodisiac and decided to find a fellow cultivator she liked to help her relieve it, this sickly contract partner clutched her sleeve. His eyes were damp with restrained emotion as he rasped, "Sister-in-law, I'm good at this too. I'm no worse than anyone else." - Xie Zhilin was born in the filthiest depths of the yin realm, abandoned by humans and gods alike. From birth, he was imprisoned in a forbidden place in the back mountains, and his elder brother decreed that he must never set foot down the mountain for the rest of his life. One day, someone broke into the forbidden grounds, gave him an immortal bone, taught him the Way, and treated him well. Not long after, his usually aloof elder brother brought him to the front mountain and pointed to the woman he regarded as a goddess. "Call her sister-in-law." At first, he thought: It wouldn't matter if she treated him like his brother. If his brother could have her, so could he. Later, when he met his brother again, only one thought filled his mind: Kill his brother, and then she could belong to him alone. - Much later, Xie Zhizhu asked, "I heard you have a new love?" Shen Yan smiled cruelly. "Yes. Your younger brother." They say that on that day, the usually pure and untainted Immortal Venerable Xie Zhizhu was covered in blood, driven mad for the wanton new Demon Lord, exactly as he had been when he learned that his cultivation partner's soul had shattered. Content warnings: sister-in-law romance, the female lead is not a virgin but the male lead is, and some delightfully familiar romantic rivalry Theme: What you can't forget will surely echo back