Who is the eldest son of the moon?

Yong Cheng. The Moon Rises into the Sea is a legendary drama in ancient costume, starring Leo and Zhao Lusi. In the play, the eldest son of the Cheng family was a general before the war. It tells the story that the daughter of a young businessman, Cheng Jia, was abandoned by her parents because of the war and became a "left-behind child", and her aunt indulged her in cruelty with the intention of cultivating her into a disabled person.