As a person who loved reading novels, I didn't store all the information I had learned from novels. However, according to the information you provided, I can try to help you find a novel called " Reincarnation of the Demon World." The protagonists of this novel were a pair of siblings. The elder brother was called Li Xiaofeng and the younger sister was called Li Xiaoting. In the novel, they traveled to a fantasy world where Li Xiaofeng and Li Xiaoting learned magic and joined a battle against evil forces. If you have any other information or specific plot requirements, please let me know. I will do my best to help you.