Abyss Devouring the Sky

On the top of Xuanshan Mountain, a young man broke into the black abyss alone to save his sister. I thought I was in a desperate situation, but I was unexpectedly rescued. Who is she? Why did she save me? My sister's life hangs on a thread, and God is unfair. Since this world does not provide a way for people to survive, then I will swallow this heaven, and I will become the heaven!