The Return of the Demon Lord? No, It's a Doting Girl.

[Urban cultivator + sister-loving maniac + invincible] Ten years ago, my sister Lu Yun's best friend Mu Yunlan committed suicide by jumping into the river. Lu Zheng sacrificed his life to save her. Mu Yunlan regained consciousness after being rescued ashore, but Lu Zheng turned into a vegetative state. Although Mu Yunlan later tried to help Lu Yun in various ways, he was rejected by the latter, and the relationship between the two broke down! Lu Zheng has been sleeping for ten years. His younger sister, who just finished the college entrance examination, gave up going to college and worked part-time to take care of her. She spent all the family savings and sold the property left by her parents. She only ate one meal a day, but she still didn't give up. What she didn't know was that after Lu Zheng and Mu Yunlan fell into the water ten years ago, they were reincarnated together into a world of immortal cultivation called Dahuang. Mu Yunlan quickly rose up as a celestial being, and achieved the position of Immortal Emperor of Yunxiao smoothly. However, Lu Zheng's talent was mediocre, so he could only find another way, killing for thousands of years, and becoming the Sky Burying Demon Lord, just so that he could master the absolute power and return to his ancestral star to take care of his sister. After becoming strong enough, he found the most powerful Immortal Emperor Yunxiao in the world, launched a shocking battle, successfully reversed time and space, and the two returned to their ancestral star. It's just that Mu Yunlan returned to the day at the beginning of the time travel, but Lu Zheng's return was delayed by a full ten years. After waking up, Lu Zheng learned about everything his sister had done for him, and he just wanted to pamper her to heaven! Invasion of all races? Then let these ten thousand races become the nourishment for my sister's cultivation!