Alchemy of Souls is a South Korean romance fantasy drama running two seasons on Netflix. Season one is 20 episodes, season two is 10 episodes, and each episode is about 1-1/4 hours long.

In a mythical land there is an Emperor and the Royal Family and there are mages in various houses.

Mage Assassin Nak-su (Go Youn-jung) is finally caught by the mage guild and after being pursued she is wounded and cornered. But she use the forbidden Alchemy of Souls to exchange her soul into the body of Mu-deok (Jung So-min, who thereafter is Nak-su throughout season one). Nak-su is stuck in the comparatively frail body of a blind woman with no magical powers.

Hiding out she runs into Jang Uk (Lee Jae-wook), the scion of the Jang mages who are foremost in the mage guild. But Jang Uk's magic was locked out by his father (who then disappeared) and he's been trying all his life to find a master who can unlock his magic. Having failed with 12 masters Jang Uk recognizes that Mu-deok is really Nak-su but instead of turning her in he makes a deal: he wants Nak-su to be his master and help him unlock his magic.

So the series is about Nak-su hiding out as Jang Uk's new servant, teaching him secretly — first discipline and fighting, then unlocking his magic through trickery, then teaching him various magical arts. She is a harsh master who often puts Jang Uk in danger but she also puts herself in danger to spur him on. Naturally a more romantic attachment starts to form because Nak-su is not really a bad person but has justifiable hatred for the mages who murdered her father whilst Jang Uk is not the lazy dilettante that he portrays to others.

I love the first season. Nak-su is a great character and Jung So-min is so freaking good (she was also great in Because This Is My First Life and good in Love Next Door). I'd say if you watch episode 19 and then stop that's a good ending point as it's a soft ending leaving everyone happy.

Episode 20 changes it to a bad ending so that we can have a season two. Now Nak-su is played by Go Youn-jung (still in the same body but due to blah-blah-blah her outside appearance now reflects her inner spirit). One the one hand, since Nak-su has amnesia and it's been three years, when she meets Jang Uk again they don't recognize each other. He's still mourning for Mu-deok who "died" but Nak-su keeps reminding him of his lost love. Meanwhile the same bad guy Jin Mu (Jo Jae-yoon in an excellent evil baddie over-the-top portrayal) still wants to control the Emperorship using the Alchemy of Souls.

Season two is still fine viewed standalone (and it's half the length since a lot of backgrounds carries over from season one) but suffers in comparison with the great season one. So it's not like I regret watching it.

Oh, I like the romance subplot between Maidservant Kim (Oh Na-ra), who is like a mother to Jang Uk, and Jang Gang (Joo Sang-wook) who is the current head of the family (and he is not Jang Uk's father). They both like each other but don't say it and he's rather oblivious to all of her hints.

Anyway, Alchemy of Souls is one of the best Korean series I've seen and there are lots of good Korean series.