I think one question can solve all the mysteries.
How and why did Mudeok (now confirmed as Buyeon) appear when Naksu was performing the alchemy of souls?
List of the things confirmed on episode 9:
- Mudeok is Buyeon.
- Buyeon is blind, or atleast blindfolded as a child
- Buyeon is a powerful young mage.
- The ice stone wasn't inside the Jin vault.
- Naksu now knows Uk is in love with her.
I believe Buyeon disappeared after that encounter with Jinmu in the lake. Jinmu secretly took her there to find the stone for his own wrong reasons. The Jin family is clueless about this since there's no suspicion between them. Mother Jin trusts Jinmu instead. Jinmu might be taking away the stone from Buyeon, but she chose to protect it. They had a fight and she ended up falling into the lake. In between these events, she managed to put the stone inside herself. Then she fell unconscious and the flow current brought her to the Sari Village. She lost her memories when she woke up and the only identification of herself is the embroidered eye mask.
It seems that Buyeon can handle the powers of the ice stone considering that scene. So she may had intentionally put the stone inside her.
I wonder if Buyeon can open her eyes or anyone has seen the color of her eyes.
These days, I keep on thinking that Naksu would die at the end. Because she should be dead if not for the spell. She also technically has no body based on what were shown up until now. I can almost accept that she would.
Jang Gang accidentally shifted the soul of Naksu's father (?) Because why would he cry over his dead body? That might be start of conflicts between the leads.
I strongly believe there are some secrets with Naksu's birth.
The ice stone might be something like a venom. It can induce the soul shifting but it can also repel it. However, it requires advanced skills.
I am bit confused with Naksu's motivations rn. She already knows there are enough reasons for his father's execution so there's no more rage in her. She might just be fighting for her survival, to avoid putrefaction. But what's the reason of living? She has no family and no reason for revenge, unless her target now is Jinmu. I wish the show would clarify this.