In ‘Alchemy of Souls’, before Naksu became an assassin, she was known as Cho-yeong. She gave up that name when her father was murdered.
Naksu was a soul shifter who took over the body of a blind girl, Mu-deok. At the end of the first part, Naksu and Mu-deok were assumed dead.
However, in part two, it is revealed that Naksu is alive; she is living as Bu-yeon, the heir to Jinyowon. Since she lost her memories, she does not remember anything about her previous life. She truly believes herself to be Bu-yeon.
With the new part of ‘Alchemy of Souls’, the viewers are treated to a different side of Naksu, as she is no longer the powerful assassin that she used to be.
Before Naksu became the Shadow Assassin, she was an ordinary young girl named Cho-yeong. Her father, Cho Chung, was a constellation recorder mage; he used to record the position of stars in Cheonbugwan.
She remembers the day when a lady hid her and asked her to run if she came across her father. From her hiding place, a terrified Cho-yeong saw her father being murdered by the four great families of Daeho.
Left all alone with no help or support in the dangerous valleys of Danhyanggok, she was offered help by Jin Mu. He promised to make her strong if she agreed to follow him. Cho-yeong accepted his help; he took her in and provided for her.
She trained all her life to become the infamous assassin; she transformed into Naksu from Cho-yeong, an innocent child.
The truth about Cho Chung’s death
Years later, when Naksu is living as Mu-deok, a petrifying Gil-ju tells her the truth about her past that she never knew.
He reveals that Naksu’s father was a soul shifter just like her. One day, he ran wild and murdered everyone around him; that is the reason Naksu was hidden that night and asked to run as soon as she saw him.
Park Jin had to kill her father to control him and prevent any more deaths. Her father then turned into stone. Gil-ju predicts that since Naksu is also a soul shifter, she would meet the same fate as him and petrify eventually.
Naksu realizes that she gave up her life as Cho-yeong believing a lie. At the end of part one, Naksu in Mu-deok’s body starts petrifying just as Gil-ju had predicted.
Now that Naksu is living as Bu-yeon and does not remember being an assassin, a different side of her personality is seen. It is a question worth asking whether she would have always been like this if she had never been an assassin and lived her life as Cho-yeong.