Very similar characters and themes of fate and sacrifice, and finding your loved one through multiple lives /over time. I personally liked the visuals better in Song of the Moon. I suspect this would have been more popular and well known if it hadn't been overshadowed by Love between a Fairy and a Devil, which came out around the same time. FYI this has two possible endings and you can decide which you prefer (which may also be why it doesn't get the attention it deserves). An underrated drama, and a good watch.
The last immortal follows the characters from Ancient Love Poetry - if you want to know what happens to Shang Gu and Bai Jue's kid, this is the next installment of the story
