Fairy in the Shell

If everyone in the world cultivates immortality and ascends to heaven, they can ascend to the immortal world and enjoy eternal life. Only my sister advised me never to ascend. She was once the most outstanding genius in the world. After passing through the tribulation and ascending to heaven, she became completely blind and paralyzed. She had been lying on the bed for more than ten years. When she was dying, she only left me this warning. When I walked out of the house, I looked up and saw a giant tree that spanned the sky and the earth, and its crown reached straight into the sea of ​​clouds. Under the tree is the mortal world, and above the branches is the forbidden realm that no one has ever set foot on. What kind of mystery is hidden in the tree, my sister is silent, and I have no way of knowing. Others are praying to become immortals, but there are no immortals in the world. Step by step, I walked towards the tree.