SeRyun has long brown hair and black eyes. She is always dressed in beautiful and elegant hanboks, as befits her social standing. She is always shown wearing a large bow in the back of her hair, usually red, but occasionally white.
To the casual observer, Lady SeRyun is a charming and beautiful young girl, but in reality she is cold, manipulative, and very ambitious, willing to do anything it takes to get what she wants. She is also shown to be quite observant of the people and events around her.
SeRyun is also domineering when it comes to her father, who caters to his spoiled daughter.
Nabi watches from the Councillor's residence as Treasurer Hak-Gyu Kim and Defense Minister JiHyun Wi, neither of whom were named in the covenant, arrive at the palace. She notes that the Left Ambassador's men are absent, which seems to confirm that his daughter is the Queen Mother's choice of bridal candidate.
The two bridal candidates meet at the queen mother's quarters, and both Lady Danah and Lady SeRyun introduce themselves to the queen mother, who compliments them on their beauty and asks them to assist each other and do their best to help His Majesty. The royal servants suddenly arrive with a royal decree announcing a third candidate: Princess HyunBin. Lady SeRyun attends the banquet later that night and witnesses the king's drunken debacle. The next day, she observes the king dragging Lady Danah away.
On another day, Lady SeRyun arrives at the table where the other two bridal candidates are waiting for a meeting with the king. A servant serves a rare tea to the ladies, and SeRyun makes a remark about its lovely fragrance. She asks HyunBin if she knows its origin, since Seo Seo is famous for its tea. HyunBin suddenly declines to drink it, and yanks the tablecloth to prevent Danah from drinking it as well. SeRyun asks if Danah needs a doctor just before the king arrives, angry at all the commotion, and orders everyone to return to the palace. Once everyone else is gone, SeRyun spots a cup of spilled tea on the floor, and kicks it into the nearby pond.
As Lady Danah works in a patch of dirt by her palace residence, Lady SeRyun approaches and asks what she is doing there. Danah replies that she is planting medicinal herbs that are normally found outside of GaGook, and that they might help people even a little in case of another plague. Lady SeRyun expresses admiration for thinking of the people, and asks to join her. Later when Danah is away, SeRyun plants seeds in Danah's garden as her maid waits quietly behind her.
Later on, Lady SeRyun meets with the queen mother at her residence. Princess HyunBin sees her leaving and finds it suspicious since the queen mother did not favor her before.
Immediately after the queen mother meets with the Left Ambassador and makes her choice for the bride (implied to be Lady SeRyun), she mysteriously collapses. As a result, King JinWon announces that he has chosen Royal Consort HyunBin as his new queen. Upon hearing the announcement, the Left Ambassador rushes to his daughter's residence. SeRyun accuses her father of getting her hopes up for nothing, but he retorts that the queen mother promised, and that he could not foresee her collapse. He then accuses her of not making any effort to win the king's favor. She tells him to calm down, and that it is not over yet. The next morning, the baby prince is found dead, having been poisoned, at Princess HyunBin's residence. The king is furious and locks down the palace.
Inside her residence, Lady SeRyun begins to giggle, then laugh heartily at the news of Lady Danah's arrest for the murder of the prince. She tells her father that they almost have the world in their hands, so he must eliminate their only witness—her maid. In the night, the maid runs for her life as the Left Ambassador and several soldiers give chase. The maid trips, and watches the swords swing towards her, but she is saved by the Crimson Moon. The Left Ambassador catches up but finds all the soldiers dead. Nabi later appears at Princess HyunBin's residence carrying the maid. Nabi explains that the only person happy with the current situation at the palace is Lady SeRyun, and offers her maid, who is refusing to talk, as evidence that SeRyun is the baby prince's real killer. Nabi makes a deal to turn herself in as a ruse and save Danah in order to gain the princess's cooperation.
- ↑ Twelfth Night, Season 2, Episode 33
- ↑ Twelfth Night, Season 3, Episode 49
- ↑ Twelfth Night, Season 3, Episode 50
- ↑ Twelfth Night, Season 3, Episode 51
- ↑ Twelfth Night, Season 3, Episode 54
- ↑ Twelfth Night, Season 3, Episode 56
- ↑ Twelfth Night, Season 3, Episode 57
- ↑ Twelfth Night, Season 3, Episode 62
- ↑ Twelfth Night, Season 3, Episode 63
- ↑ Twelfth Night, Season 3, Episode 64
- ↑ Twelfth Night, Season 3, Episode 65
- ↑ Twelfth Night, Season 3, Episode 71
- ↑ Twelfth Night, Season 3, Episode 77
- ↑ Twelfth Night, Season 3, Episode 79