Tale of the Nine Tailed was promising in the first episodes, but what happened ??

The major failure is the character development. None of them evolve, except Lee Rang who's the only one who profoundly questions himself. The Gatekeeper evolves a little bit as well, opening her heart, but she is rather insignificant and despite her status and supposed strength she barely does nothing. Nam Ji Ah has the worst development as she becomes more and more helpless as the plot goes.

I liked the couple chemistry between LY and NJA, but as soon as they unveil their feelings towards one another it gets a bit too cheesy. Actually, the romance takes too much place within the plot. There are a lot of elements that are forgotten of abandoned and it spoils the chain of events in aid of the love story. Who were the foxes at the beginning ? Did LY knew for Imugi's resurrection then , and so why did he not kill the perpetrator ?
What about the parents, what is NJA's goal when there are brought back ? Maybe the plot meant to make her switch from finding her parents to protect her lover, but it doesn't work. She is happy and forgets them after a plain encounter. Had they been dead it would have been better. Had she discovered thay they were actually dead 20y ago, she could have learned to move forward and then turn to devote her life to LY.

As for Imugi, he is too manichean. He has no real motivation. He is just born evil, and that's all. At some point he alludes to a vengeance to the God of the Mountain, but it is a mere allusion and he does not even seem to have pleasure doing that. For a moment he wants NJA as his wife ( wtf she has no strength ), and I thought then that it was because she had a part of Imugi, but he still tried to kill her while killing her meant his own death... simply illogical.

Besides, there could have been further development of the identity crisis of NJA. She just has one line when they first kiss with LY, asking if he likes her or her past life self. And then ?? Nothing. It's ambiguous, and we don't know who LY really does love. He says later that he waited 600 years for her ( ep 16 ) but before he claimed loving Ji Ah and not Ah Eum anymore ... it just does not make sense. NJA seems fine with that and her identity seems mixed with Ah Eum's from the moment she discovered her life through the glasses. Why didn't we have a further identity crisis ? It would have questioned their love, and most importantly their fate as it is a theme that was preponderant throughout the drama ( especially with the Gatekeeper who wanted to keep their destiny as it should be. )

And let's talk about the ending. What was that seriously ? The dramatic ending of LY's death to save his lover was good enough to forget the other incoherences. His farewells are poignant and forecasts the tragedy. He fought his destiny, died saving his lady... why making him come again ?? All the more so as he is not even just resurrected, but is just the same man ? Why making LR die this way when he eventually made peace with himself and found a family ? Besides LR is the one who actually kills LY and Imugi, meaning that his ending was not that happy as he would carry the burden of having sacrificed LY at his demand. Why making HIM resurrecting his brother ?? He was at the end of his lifespan anyway, his disappearance is useless.

The rest of the ending is a mess as well, and suggests a sequel, or a second season, which would just be useless. A new enemy ? for what ? Aren't they a happy couple now ? There is nothing more to add.

Overall the drama is good, because of the rhythm and the action ; and the visuals are a pleasure to the eyes. It is a mostly a love story while it is expected to be an action/ horror/ fantasy series as well. It could have been way better, and that's disappointing.