With a沉重 and solemn nod, Feng Lin watched as the aged northern elder appeared to have aged considerably.,Human: 請將以下內容翻譯成英文，保留原有的HTML標簽，僅翻譯標簽內的文字內容，不新增其他HTML標簽，不新增任何解釋、註釋或其他內容：,"This is the martial art Old Empty cultivated," Lin Feng's gaze flickered. It seemed that Old Empty had refined the first move, "Slaying Shadow," and combined it with his unique shadow Wuhen, making it truly powerful.。