Read manga: The Cloud That Became Rain

manga
Summary:

Sometimes, not even reincarnation is enough to get the blood off your hands. A love blossoming between an emperor and a former child soldier comes to a tragic end during a merciless war. However 400 Years later the soldier is reincarnated with faint memories of his past life, and sets out to uncover the mysteries surrounding the fate of his long dead love. Along the way he is accompanied by a mysterious man who seems to know a little bit more than he lets on.