I highly recommend this show.
This was one of the first shows I watched when I started watching Kdramas. This was the first supernatural/fantasy genre Kdrama I saw so I was very sceptical but I LOVED it.

The story was so captivating. The casting was perfection and all the cast members knew what they were doing.
The back and forth between the modern timeline and ancient timeline was so well done.
The highlight of the show for me was the bromance between the goblin and the grim reaper.
The love story was between the goblin and the main FL was fine (once you get past the creepy age difference). I preferred the love story of the second ML and FL more.

A good story makes or breaks the show for me but OST makes it unforgettable. This show has arguably one of the best OSTs. It still gives me goosebumps.

Definitely a MUST-WATCH!!!!