I think you mean Li Yu, also known as Song Huizong, the last emperor of Southern Tang Dynasty.
Li Yu is regarded as a man with a pure heart, because he loves his country and people, literature and art, and has the spirit of unremitting efforts for the development of the country and the nation.
He actively carried out cultural undertakings, which promoted the development of literature and art, especially Ci, one of the cultural representatives of the Southern Tang Dynasty. He was a talented poet himself, and he also had considerable attainments in calligraphy and painting.
during his reign, he implemented the policy of cultural administration, worked hard to develop science and technology culture, advocated reform and innovation, and attached importance to the cultivation and selection of talents. He also personally wrote many famous lyrics and songs, which showed his love for culture.
Although he is not decisive in politics, there is no doubt about his love and concern for the country and the nation. He lived a rough life in his later years. After the downfall of the Southern Tang Dynasty, he was captured to the north, but he did not give up his loyalty to the Southern Tang Dynasty and his love for the nation. He tried to escape many times and was finally forced to commit suicide.
His loyalty and patriotism reflect his childlike innocence. He has deep feelings for his country and people, so he is considered a man with a pure heart.