This drama is definitely overrated. There are many famous actors actresses are involved in the production to promote the series.  The series itself also based on a based selling novel, City of Fantasy.  For my review, let's divide into pros and cons.

Pros:
1. Amazing concept
2. Costume and character design is really beautiful and fantastic
3. Amazing special effects and animation
4. The action scenes are pretty cool
5. A lot of famous actors and actresses are involved in it. If you are a fan, you would like to watch it.

Cons:
1. The plot is complex
2. Ending is weird and unclear
3. Too much annoying character
4. The story can be too cheesy and sappy

In the end, this drama is a failure to me. Despite the great concept and beautiful imagination, it offers me, but the story just fails me hard.