|“||Ultimately, every human is their own writer.||”|
At the end of the novel, it is revealed that she also wrote the webnovel Three Ways to Survive in a Ruined World under the pseudonym tls123, though she was not aware of this until long after its completion.
Han Sooyoung can change the appearance of her Avatar clones, causing her to wear and shed many different appearances. In her true form, she is petite, thin, and nicely proportioned, described as rather beautiful. She has a small face with sharp canines and white skin. Her eyes are large with their corners angled upwards, with a beauty mark underneath one eye. Her hair is short and fine, black in color, and just reaches her shoulders.
She originally wears jeans, which are ripped after her experience in the coin farm. After Peace Land, she wears a blue combat suit. Later on, she takes to wearing lensless horn-rimmed glasses. After the end of the scenarios, she switches these out for a pair of plain black glasses.
Han Sooyoung's appearance in the 1863rd round is virtually identical to her 3rd round self. She has a bob cut and wears the white Infinite Dimension Space Coat along with a half-mask. After Yoo Joonghyuk's regression, she wears a hat tilted down over her face, presumably to hide any evidence of her crying. At some point after Kim Dokja's departure from the 1863rd round, she dons a black coat instead.
Han Sooyoung's appearance was much the same at 13 years old; though obviously appearing visibly younger, she had the same shoulder-length bob haircut and beauty mark as her elder self.
- Author: An attribute gained through the sincere desire to write a new story. Han Sooyoung presumably has this due to authoring the novels Ways of Survival and SSSSS-grade Infinite Regressor.
- Avatar: Individuals with the Author attribute automatically gain the exclusive skill "Avatar". Avatar allows its user to split off clones of themselves and shape their appearance; the only condition is that the clones must be supplied with one or more memories belonging to the original user of the skill. The more memories a clone is given, the greater its autonomy. The original body can access the clones' senses and remotely control them.
- Han Sooyoung is also able to use the Avatar ability in a unique way; instead of splitting off physical clones of herself, she activates the skill inside her own head and splits her mind into infinite clones, allowing her to talk to versions of herself. Through extensive rapid discussion with her other selves, she is able to suggest and predict events that may occur in the future, since as a writer she is aware of how Stories created in the <Star Stream> would most likely unfold. This skill has gained an associated story, called 'Predictive Plagiarism'.
- Eye of Truth: An attributes-detecting skill, similar to Yoo Joonghyuk's [Sage's Eye] and comparable in power to Anna Croft's [Great Demon's Eye]. Causes one of the user's eyes to turn a brilliant blue, glowing bright enough to provide light when in dark places.
- Poker Face: Allows the user to block assessing skills such as [Lie Detection] when directed at the user.
- Lie Detection: A B-grade skill that, as the name suggests, allows the user to identify the veracity of statements made in their vicinity.
- An unnamed skill allows Han Sooyoung to read the attributes and information of those who stopped reading Ways of Survival before her; she claims that this is a privilege granted by her status as the last person to stop reading Ways of Survival.
Sponsor: Abyssal Black Flame Dragon
- Black Flames (Stigma): Allows the user to summon powerful black flames that can be manipulated at will, even infusing weapons with them.
- Advent of Half-God: Abyssal Black Flame Dragon can manifest part of his consciousness into Han Sooyoung. This allows the duo to work in tandem, freely using the Abyssal Black Flame Dragon's powers. The Advent alters Han Sooyoung's appearance and behavior, dyeing her irises purple with demonic energy, and tends to cover half her face with one hand, often cackling maniacally. The bandage she wraps around one hand begins to unfurl. She also begins to emit a demonic aura. The Advent requires an incantation to be recited in order to allow the Abyssal Black Flame Dragon to descend; Han Sooyoung notes that this incantation is rather lengthy. Han Sooyoung has used this ability twice: once during the Demon King Selection arc, and once during the Great War of Constellations and Demons.
- The incantation is as follows: "I, the master of the Black Flame, Han Sooyoung, shall awake the Dragon of the ancient seal! Oh, the constellation darker than darkness itself, oh, the abyss deeper than the flowing night… Here in this place, reveal yourself!  […] Oh, the noble and majestic master of the dark clouds, Black Flame Dragon […] The darkest dark, the most legendary tale, greatest Dragon among them all, the blessing of the Black Flame Dragon shall accompany this body […]" 
- Dark Shadow Phoenix: Abyssal Black Flame Dragon's shadow manifests as a physical black dragon, dozens of metres tall. It can use Dragon Breath at will, powerful enough to turn Valkyries to dust within seconds.
- Fires of Red Flames: Possibly its own fire-breath ability, or a buff for Dark Shadow Phoenix which strengthens its breath ability.
- "The darkest dark! The legend among legends! Fires of Red Flames!"
- Han Sooyoung has been noted to have particularly high Magic Power, which is used to power her Avatar clones.
- Her stamina is somewhat low.
- Torch That Swallowed the Myth (Giant Story): Has shares in this. Acquired upon finishing Gigantomachia and defeating Poseidon.
- Predictive Plagiarism (rating unknown): Originally acquired by the 1863rd round Han Sooyoung and passed on to her 3rd/1864th round self. Aids Han Sooyoung in predicting the future through internal application of the [Avatar] skill.
- Disciple of the Legendary Swordmaster (rating unknown): Origin unknown. Earned at some point prior to arriving on Reincarnation Island.
- Ultimate Lie (rating unknown): Origin unknown. Used by the 1863rd round's Han Sooyoung when constructing a replacement for the Fourth Wall.
- Revision Specialist (rating unknown): Origin unknown. A Story associated with writing.
- Guide of the Line Spacing (rating unknown): Origin unknown. A Story associated with writing. Also translatable as "Guide Between the Lines".
- Han Sooyoung has a habit of writing down short sentences on her smartphone when she is struck by inspiration.
- The 1863rd Han Sooyoung smokes when she is stressed.