It's nice to see a fantasy twist in a K-Drama like Alchemy of Souls. Power is the focus of the series, as it is of most Kdramas during that time period. There are different kindoms that seem to want to get along for the greater good. However, greed, control, and power play a role in complicating things.

In addition to the four seasons, the characters have various talents, strengths, and weaknesses. The show's attention is mostly focused on Jang Uk (Lee Jae Wook) and Mu Deok (Jung so Min). The assassin Naksu initially appeared to be the center of attention, but that was not the case.

The series didn't pan out quite as I had hoped, even though I enjoyed it. Maybe I should have paid more attention to the synopsis. I was hoping that Naksu aka-Mu Deok would remain steady on her mission as the basa$$ assassin she showed very briefly in episode 1. After switching souls into Mu Doek, she conveniently loses her power.
Over the next dozen or so episodes, she was primarily focused on being a maid. As well as training Jang Uk. So, I'm thinking that they don't want to show Naksu in all her glory just yet, since that would overshadow Jang Uk's arc.

While they fall in love, let Jang Uk gradually rise to power. Naksu would then be able to regain her power and assist Jang Uk in defeating Jin Mu and his minions! It's a cool and understandable method. NOT! Her power is regained alright... This isn't a deal breaker, since I knew there would be a season 2. Yeah, I guess (uh-huh).

The production of Alchemy was nevertheless very good. A fantasy filled with action, love, funny moments and fantasy. Acting and chemistry between the leads were good, but not the best I have seen. Park Jin and his Headmaid servant Kim exhibited cuteness. The series development was so deep, at one point I even though if the FL did die during the demonstration, would it really effect the main story much? We seemed pretty much way past major effectiveness and the events of Mu Deok. (priestess or not). That's the scripts fault not actors.
The visuals in Alchemy of Souls are stunning. The production design is stunning, with detailed and immersive sets. The special effects are pretty effective, enhancing the magical elements of the story. It all made the fighting nice.

But Overall, The Alchemy of Souls series is a well-developed enjoyable series with intriguing characters and a captivating plot. Although I would have given it another .5 in the ratings, I was disappointed with how they left me hanging with Naksu. And the ending mmmm...