Ha Saetbyul

Biography

The life that Yu Jitae remembers

Yu Jitae later describes a Ha Saetbyul from the second iteration, making that history a revealed context for his reaction to her rather than the beginning of her present life. She had cared for children at an orphanage before awakening the Danger-sensing Eye, then volunteered for the military after Chungcheong was partly destroyed. Although frightened by battle, blood, and injury, she supported her unit as an operator and gradually entered a relationship with its commander, Yu Jitae. They promised to build a family after the war. (Chapter 23)

That future ended when a catastrophe-level demon captured their unit. Despite being the most fearful member, Saetbyul offered her life in place of Jitae's, an act that exposed the courage beneath her timidity. The demon controlled Jitae and forced him to torture and kill her, leaving the words “I'm cold” as one of his enduring memories. This tragedy belongs to the lost second iteration; it explains Jitae's guilt and recognition when the seventh iteration places another Ha Saetbyul before him. (Chapters 23, 44)

Prototype X and the battle in Hetheia's Ocean

In the seventh iteration, Association fire destroyed Saetbyul's orphanage and killed the children under her care. She blamed both the superhumans responsible and herself, then contracted with Lakshata out of hatred. The contract erased most of her memories and turned her into the female Prototype X, or Number 42, a designation for Saetbyul while corrupted rather than another person. Placed in a raid as its operator, she still displayed fragments of her familiar nervousness, but the persona directing her actions belonged to the demonic corruption and the hostile authority acting through it. (Chapters 47–48)

During the raid on Hetheia's Ocean, corrupted Saetbyul used her eye to monitor threats and weakening allies until the Kraken battle created an opening. She released poisonous black fog, underwent Extrication, and attacked the raid party with an enlarged armoured body and multiple thorned tentacles. Jitae dragged her into mana-dense deep water, where the commanding link of Prototype X could not function, and deliberately avoided attacks likely to kill her. When the invading Hostility used her borrowed memories and voice to torment him, he recognized that Saetbyul herself was not controlling the confrontation. (Chapters 48–50)

Jitae allowed Arma's Longsword to wound her without striking a vital organ, followed the intruding Hostility into the Abyss, and shattered the sword to sever its connection to her body. He then forced Lakshata to annul their contract and carried the unconscious Saetbyul away. She awoke free of the demon's power but still suffering Mental Contamination, which distorted her language and conduct. After Yeorum restrained her, Jitae placed her and the similarly contaminated Protector under the Light of Paradise in his underground labyrinth. (Chapters 49–54)

Choosing a future inside the labyrinth

The Light of Paradise made Saetbyul continuously content but did not erase the grief beneath her contamination. She automatically cleaned, searched for children who needed help, and sang lullabies, preserving the habits of her old vocation. BM, who brought food and watched over the patients, noticed the contradiction when she smilingly asked him to kill her. In conversation with Jitae, she recalled the orphanage's destruction, admitted that she feared living with those memories, and resisted erasing them because the dead children would otherwise have no one left to remember them. (Chapters 67–69)

Rather than giving her a prescribed answer, Jitae asked whether she still had anything worth expecting from life. Saetbyul decided that she wanted to change an era that allowed other caretakers and children to suffer as she had. Recognizing that the goal was larger than her immediate power, she chose a practical first step: apologizing to an Association soldier she had threatened and training with the thirty-member special-force squad. Her decision did not cure the contamination, but it replaced passive despair with a direction she could pursue. (Chapter 69)

Training at Happy Happy Fitness transformed Saetbyul from a small, hesitant woman into a heavily conditioned superhuman. She found community among the squad, shared their devotion to Kaeul, and retained her instinct for childcare: when Jung Taebaek cried, she soothed him, taught him songs, and later helped him learn letters. She also supported the Protector when it left the labyrinth. These acts show her caretaking identity surviving both the artificial happiness around her and the years of confinement. (Chapters 84, 98, 101, 142–144, 187, 192)

When the contamination and the Light's lingering influence finally dissipated, Saetbyul was physically strong but emotionally exhausted, homeless, unemployed, and without surviving acquaintances. Clone 2 carried her out, argued through her fears, and spent two weeks helping her establish a home and work. Saetbyul rejected military service and personal training, choosing instead to teach at an underfunded orphanage because that small community was the part of the world she believed she could actually change. Their parting was delayed by a farewell drink and the beginning of mutual attachment. (Chapters 250, 266–267)

A deliberately smaller world

By the time Clone 2 returned to his other duties, Saetbyul had a furnished one-room home, a power rack she insisted on keeping, a position at Goseong Province Orphanage, and new people around her. Clone 2 later reported that helping her settle and work had become an emotional exchange rather than a purely assigned task. Their near-kiss while drinking stopped before either crossed the boundary, and Saetbyul's question about whether they would meet again turned their farewell into an unresolved promise rather than a clean ending. (Chapters 307, 314)

Saetbyul does not return to the conflicts that dominate the later period, and her chosen life remains outside the main battlefield. The relationship nevertheless leaves a lasting effect on Clone 2: after their separation, he asks whether parted people can meet again, and the memory stays with him during a later ordeal. Her development therefore ends not with recovered rank or renewed combat service, but with the quieter success she defined for herself—caring for a reachable community while another person genuinely hopes to see her again. (Chapters 314, 366)

Appearance and personality

Saetbyul is short and has a cute, rabbit-like face; she is twenty-six when identified as Number 42 and thinks she looks slightly older than her age. As Prototype X, thick full metal armour covers her from head to toe while its tailored shape still marks a feminine frame. Extrication enlarges both her body and armour and turns the metal into tentacular appendages. After sustained training, she remains short but develops broad shoulders, firm arms, and a compact, visibly muscular build. (Chapters 47–49, 51, 69, 142, 266)

Her ordinary temperament is gentle, timid, and nurturing. She fears deep water, blood, sharp objects, childbirth, and remembered injury, often twisting her hair or laughing “hihi” when uneasy. Yet fear does not make her indifferent: she volunteers for military service in the revealed second-iteration history, offers herself for another person, and repeatedly returns to caring for children. Her self-blame can become destructive, but she is also candid, dryly humorous, stubborn about her choices, and capable of turning an immense ideal into modest daily work. (Chapters 23, 48, 51, 67–69, 266)

Her conduct while possessed or mentally contaminated should not be treated as a complete expression of this personality. Prototype X's predatory surveillance, the Hostility's taunts in her voice, and her violent awakening all arise while external powers control or pollute her. Even then, her comparatively restrained threats, compulsive cleaning, lullabies, and concern for children reveal traits that the corruption does not fully suppress. Once freed, she regains enough clarity to reject careers others choose for her and define her own measure of meaningful change. (Chapters 49–51, 67–69, 266)

Powers and abilities

Danger-sensing Eye and operator work

Saetbyul's awakened blessing, Danger-sensing Eye, makes her a rare operator-type superhuman. It senses approaching enemies and can interpret a person's impending death as a risk factor, allowing her to direct a unit and monitor battlefield danger. Prototype X weaponizes the same perception to identify exhausted allies during the Kraken raid. The eye provides awareness rather than a complete combat solution: Saetbyul still depends on a team, and her fear and limited personal strength originally made front-line combat difficult. (Chapters 23, 48–49)

Corrupted demonic capabilities

As Prototype X, Saetbyul is a commanding-type transcendent-demon experiment intended to connect many demonic minds into one network. The link grows more dangerous as it gains participants, but long-distance demonic communication fails in the mana-packed depths of Hetheia's Ocean. Her Lakshata contract also grants a stronger demonic body, poisonous fog, skilled longsword combat, and Extrication: her armour and body expand while six principal tentacles emerge around her torso and shoulders, using spring-like movement, thorns, and poison for rapid close combat. (Chapters 39, 48–49)

These abilities are neither stable nor wholly her own. Lakshata supplies the power behind the contract, while Hostility can enter her body, draw on displaced memories, and speak through her. Jitae first disables her commanding link through the environment, then destroys the sword carrying Hostility and compels Lakshata to cancel the contract. Saetbyul consequently loses the demonic authority that supported her recorded world rank of 871 and is easily overpowered by Yeorum after awakening. No later scene shows her recovering Prototype X's network, demonic transformation, or former rank. (Chapters 49–51)

Superhuman conditioning

Even without the demon contract, Saetbyul remains an awakened superhuman. Years of extreme resistance training under Bell Baryon's squad greatly increase her musculature and lifting endurance; she performs hundreds of weighted pull-ups and later maintains a personal power rack. This conditioning gives her enough physical force to manhandle Clone 2 during an argument, but she does not present it as a new combat tier. Once free, she explicitly refuses both soldiering and work as a superhuman trainer, retaining exercise as part of her civilian routine. (Chapters 69, 84, 142, 266)

Power progression

Relationships

Yu Jitae

The second-iteration Saetbyul was Jitae's lover and intended future partner, and her forced death became one of his defining traumas. In the seventh iteration, he refuses to repeat that killing when Hostility uses her body and their old memories against him. His intervention saves her, and his discussion of expectation helps her choose life, but he does not resume their former romance. Instead, he entrusts her reintegration to a younger copy of himself and deliberately allows her future to develop beyond him. (Chapters 23, 48–50, 68–69, 266–267)

Clone 1 and Clone 2

Clone 1 uncovers the Number 42 profile and draws Jitae's attention to Prototype X's changed identity, indirectly making her rescue possible. Clone 2 has the more personal role: he guides her out of confinement, debates her practical fears, finds her a home, and helps make her preferred orphanage job possible. Their bickering becomes warmth and attraction, but they separate before defining the relationship; both their farewell and Clone 2's later longing leave open the possibility of another meeting. (Chapters 47, 266, 314, 366)

BM, the Protector, and the special-force squad

BM feeds Saetbyul in confinement and is the first caretaker to recognize that her cheerful behaviour hides suicidal despair. The Protector shares both Mental Contamination and confinement with her, and they acknowledge each other as beings who live to protect others before it departs. Bell Baryon and the special-force squad then give Saetbyul a demanding community in which apology becomes training, physical improvement, childcare, and shared remembrance rather than isolation. (Chapters 67–69, 84, 101, 142–144, 187, 192)

Items

Arma's Longsword

Arma's Longsword belongs to the Protector and is wielded by Jitae during the fight with Prototype X; it is never Saetbyul's possession. Jitae uses it to strip away her extricated form without killing her, but Hostility then forces the weapon toward her heart and enters her body through it. He redirects the blow away from vital organs and later shatters the sword against Lakshata's gate, severing Hostility's control and making Saetbyul's rescue possible. (Chapters 49–50)