Cheon Yo-hwa

Cheon Yo-hwa is the 113th student council president of Baekhwa Girls' High and the Korean Peninsula's only recognized necromancer. Her power does more than animate corpses: she assigns memories, rules, and social roles until the dead behave like people and the living can be rewritten. After rejecting the identity imposed by her family's cult, she claims a name meaning “a thousand stories” and eventually shares the primordial authority of Laplace with her alternate sister, Cheon-hwa. (Chapters 48–52, 87–98, and 433–435)

Biography

President of a school of the living and dead

Baekhwa Girls' High disappeared into a closed Tutorial Dungeon for eleven outside months, while its students experienced roughly four years inside. Of about 750 students, nineteen emerged, and two soon died by suicide. At the center of the surviving group stood Yo-hwa, whose rare talent for reading people, resolving internal disputes, and directing hostility outward made the remaining students rally around her as president. Their school ceased to be merely an alma mater and became a bond stronger than ordinary guild membership. (Chapter 48)

The victory preserved the school's routines in a grotesque form. Yo-hwa filled classrooms, sports grounds, shops, and security posts with uniformed corpses programmed as students, teachers, customers, and guards, while the living survivors attended classes among them. Visitors who ignored the school's rules could be assigned a new job and lose their former memories. Undertaker initially fled from the collective, then returned in a later cycle by claiming the authority of an alumna. Yo-hwa's absolute respect for school hierarchy turned the feared “Academy City” ruler into his eager junior and gave him a way to redirect her organization toward public work. (Chapters 49–50)

Under Noh Do-hwa, Baekhwa's corpses became the advance scouts of the National Road Management Corps, reducing the human disappearance rate on dangerous roads. Their inability to improvise led Do-hwa to identify them as NPCs rather than ordinary zombies: each construct could perform an assigned role with surprising depth but faltered outside its programmed situation. Yo-hwa later imprinted legal knowledge and the role of judge onto corpses, producing a distributed mediation system. The work showed that her necromancy could preserve learned behavior and institutions as readily as it could command bodies. (Chapters 50–52)

Choosing the name of a thousand stories

Undertaker eventually learned that Yo-hwa could not recognize Anomalies as Anomalies. She saw a fairy as a cat, Ten Legs as an earthquake, and the Tutorial Dungeon's horrors through mundane substitutions. Her family records deepened the mystery: her father belonged to the foundation behind Baekhwa Girls' High, the family estate concealed Taoist writings and underground facilities, and her surname had been changed from the character meaning “thousand” to one meaning “heaven.” Yo-hwa herself remembered almost nothing of her family and sincerely rejected any suggestion that a cult or fairy had shaped her. (Chapter 87)

To reach the truth before those memories were erased, Undertaker entered Baekhwa's still-closed Tutorial Dungeon with Fairy No. 264. He found a school converted into a laboratory of ghost stories, sacrificial rites, white birches, and red spider lilies. The cult had prepared Yo-hwa as an apostle and treated her identity as material for the Infinite Void. Undertaker's intervention gave her a relationship outside that design: “sunbae” became “teacher,” and Yo-hwa chose the spelling Cheon Yo-hwa (千謠話), “a thousand stories,” over Cheon Yo-hwa (天寥化), the “heavenly transformation” her family intended. (Chapters 87–94)

That choice did not safely remove the power placed inside her. Yo-hwa learned to seal ghostly beings and portions of the Infinite Void in hourglasses, then use the captive Anomalies as an arsenal. A mirror-like vessel preserved another expression of herself, foreshadowing the black-uniformed Cheon-hwa who later existed as a separate elder or alternate sister. The split made Yo-hwa stronger but also placed her close to corruption: swallowing or containing an Outer God's qualities could blur the border between the chosen student president and the cult's desired apostle. (Chapters 94–98 and 110)

The sisters and Laplace

During the battle inside Undertaker's divine realm, Yo-hwa met Cheon-hwa face to face. They shared an appearance and origin but not a single continuous personality: Yo-hwa wore the white school uniform and approached the elder's manic confidence with wary resignation, while Cheon-hwa wore black and treated their reunion as that of sisters. Cheon-hwa explained that their family's primordial deity could only be inherited completely through twins. The two therefore joined hands rather than allowing either identity to erase the other. (Chapters 433–435)

Their invocation of Laplace transformed the corpses in Undertaker's memory into a simulation engine. Sacrificed versions of the sisters could trace an enemy ability back to an origin and erase it, removing Sound Barrier, Mind Reading, and Sensory Corruption from Go Yuri's composite body. The technique was neither clean nor limitless: a failed exchange killed hundreds of simulated Yo-hwas, and its continued operation required Sim Ah-ryeon to heal bodies that were already dead. The paired inheritance made Yo-hwa an Outer-God-scale combatant only through cooperation, a prepared memory realm, and catastrophic repeated sacrifice. (Chapter 435)

Pandora's answer to failed worlds

One possible pre-apocalypse life reveals how far Yo-hwa's talent for stories could turn. As a high priestess working with Cheon-hwa, she proposed destroying the world before another catastrophe could claim it, using humanity's minds to run complete simulations and storing their memories in Pandora's Box. She did not limit the time capsule to a single romance or successful history. Her aim was to preserve the despair of Noh Do-hwa, Sim Ah-ryeon, Jeong Ye-ji, Dang Seo-rin, and every other ending that had vanished without a witness, trusting that hope could be carried inside the same vessel. (Chapters 464–473)

The plan brought her to the edge of becoming the sole Outer God. Yo-hwa and her sister refused to betray each other even when one more step would have given either absolute control. They instead split their work across innumerable simulations, recorded the dying world's memories, and buried the box for a later iteration. When it was finally opened, those impossible lives entered the alliance members who had lived them, forcing each to decide whether a simulated or discarded bond could still be accepted as truth. Yo-hwa's victory was therefore not mastery over one ending, but preservation of stories that regression had treated as expendable. (Chapters 472–481)

Appearance and personality

Yo-hwa is an orange-haired young woman who continues to present herself as a high-school student long after ordinary graduation has lost meaning. Her signature clothing is Baekhwa's white sailor-style school uniform, including the ribbon the school regards as its pride. At her first meeting with Undertaker, her dark eyes lack focus so completely that iris and pupil appear indistinguishable. Cheon-hwa has the same face but wears a black uniform, providing a clear visual distinction when the two sisters appear together. (Chapters 48–49, 87, and 433–435)

Her early manner is polite, blank, and unnervingly fixed. She can tilt her head with apparent innocence while treating corpses and living students as one school organism, and her smile initially resembles an expression assigned to a role. Once she accepts Undertaker as a senior and teacher, that reserve gives way to energetic greetings, pride in Baekhwa, sharp jokes, and visible excitement. She remains sensitive to school hierarchy and criticism of her age or presidency, but her devotion to her students is genuine rather than merely programmed. (Chapters 49–52 and 87–98)

Yo-hwa is a gifted social organizer and tactician. She reads group psychology, assigns roles, turns disadvantages into resources, and can deceive allies as readily as enemies when she believes a later revelation will produce a better ending. That confidence coexists with vulnerability to exclusion and to the family identity engineered for her. Her mature answer is not to become an isolated mastermind: she preserves both sisters, relies on fellow healers and strategists, and defines herself through the many stories she chooses to remember. (Chapters 48, 94–98, 433–435, and 472–481)

Abilities and anomalies

Yo-hwa's abilities have no universal human rank ladder. Necromancy, role assignment, anomaly containment, and the paired authority of Laplace are related expressions of her power over boundaries and settings. Their results depend on prepared bodies, stored knowledge, vessels, or a cooperating second self; the story does not establish that she can freely reproduce the full Laplace manifestation outside the circumstances of the final divine-realm battle.

Necromancy and NPC creation

Yo-hwa animates corpses by giving them roles, behavioral rules, thought patterns, and memories. Her constructs can act as guards, students, teachers, scouts, or judges and may appear convincingly human while performing their assigned work. She transmits a role through dark, serpent-like shadows that enter the target's head. Memory can be accumulated separately before the final assignment, as demonstrated when corpses listened to legal texts for a month and then received the role of judge. (Chapters 49–52)

The constructs are not autonomous people in every respect. Simple scouts cannot make detailed tactical judgments, and an unexpected question can freeze a guard whose instructions do not cover it. Their usefulness rises when the role has clear rules and sufficient information. Yo-hwa can also operate on living minds, rewriting memories or personalities strongly enough to make hostile visitors accept employment at Baekhwa. That extension makes her power strategically valuable and ethically dangerous, especially when combined with Dang Seo-rin's ability to formalize exchanges. (Chapters 49–52, 90, and 110–111)

Black magic, imposed settings, and sealing

After confronting the Infinite Void's influence, Yo-hwa expands from corpse programming into black magic that can apply a role or setting to an Anomaly. Instead of merely asking a dead body to behave as a guard, she can define how a supernatural entity is permitted to function. This same authority supports sealing: she confines members of the Hyakki Yagyo and aspects of the Infinite Void within custom hourglasses, carries the vessels on a belt, and releases or invokes their contents as situational weapons. (Chapters 94–98, 110, and 122)

Containment is not destruction. The white hourglass holding Infinite Void remains dangerous enough that breaking it releases an Outer God, while the mirror vessel associated with Cheon-hwa preserves a self capable of acting beyond ordinary human limits. Absorbing, imprisoning, or borrowing these qualities exposes Yo-hwa to contamination and identity division. Her black magic is therefore strongest when its conditions and custody remain controlled; a broken vessel can turn a prepared advantage into a world-level threat. (Chapters 95–98, 110, and 154–155)

Laplace

Laplace is the primordial authority attached to Yo-hwa's family, divided into the powers identified as Infinite Void and Mastermind. Its complete descent requires the paired bodies of Yo-hwa and Cheon-hwa. Within Undertaker's corpse-filled divine realm, the sisters use available dead selves as simulations: a sacrificed version identifies an enemy power at its origin, and the corresponding ability can be erased from the target. The authority also mocks bodily boundaries, making limbs, weapons, and forms emerge from corpses as required by the simulation. (Chapter 435)

The cost scales with the target and with the sisters' imperfect control. Removing several of Go Yuri's abilities causes hundreds of simulated sisters to die when the opposing reincarnations defeat them inside the calculation. Ah-ryeon's healing is needed to raise those dead selves and keep the loop running. Later, the same family power supports reality-like simulations and Pandora's Box, but approaching its full authority threatens to absorb Yo-hwa's self-awareness into the Outer God. (Chapters 435 and 472–473)

Power progression

Relationships

• Undertaker: Undertaker first approaches Yo-hwa as a dangerous necromancer, then exploits Baekhwa's hierarchy to become her senior. After entering the school before its Tutorial Dungeon opens, he helps her reject the cult's chosen identity. She eventually calls him teacher, serves as a major alliance combatant, and preserves failed lives in which their bond took different forms. (Chapters 49–52, 87–98, 365–372, and 433–481)
• Cheon-hwa: Cheon-hwa is Yo-hwa's elder or alternate sister, born from the same family design but developed into a separate personality. Their reunion is uneasy and affectionate. By refusing to erase or betray each other, the two become the paired human vessels required for Laplace. (Chapters 96–98, 433–435, and 464–473)
• Dang Seo-rin: Seo-rin is Yo-hwa's white-magic counterpart, rival, and collaborator. Their powers can reinforce dangerous personality alteration, while their very different guild cultures create recurring friction. Both nevertheless serve as central alliance tacticians against Fallen and Outer-God threats. (Chapters 94, 110–112, 345–369, and 433–435)
• Noh Do-hwa: Do-hwa turns Yo-hwa's corpses into road scouts and judicial infrastructure while keeping the president obedient through the authority of a supposed school senior. Their partnership converts Baekhwa's insular routines into practical systems for the peninsula. (Chapters 50–52)
• Jeong Ye-ji: Ye-ji observes Yo-hwa's movements, supports Undertaker's plans around Baekhwa, and later coordinates time with Yo-hwa during the final raid. After Pandora's Box opens, she is also one of the few allies capable of restraining both sisters' schemes. (Chapters 50, 87–98, 433–435, and 476)
• Sim Ah-ryeon: Ah-ryeon heals the sacrificed Cheon sisters inside Undertaker's divine realm, allowing the Laplace simulation to continue after failed selves die. Yo-hwa later preserves Ah-ryeon's forgotten endings as part of Pandora's Box. (Chapters 435 and 472–476)

Items

• Ghost-Sealing Hourglasses: Yo-hwa crafts and wears a belt of hourglasses that imprison members of the Hyakki Yagyo and portions of Infinite Void. She uses the sealed beings as a flexible combat arsenal; smashing a vessel can also release what it contains. (Chapters 95–97, 110, 122, and 154–155)
• Cheon Yo-hwa's Black Hair Tie: Yo-hwa leaves the hair tie in Undertaker's hand when she disappears while guiding him through the unconscious world. It becomes a protective memento and a point of resistance against brainwashing before vanishing when that unstable reality fixes itself. (Chapters 365–367 and 372)
• Pandora's Box: Yo-hwa designs the box as a time capsule for memories, love, despair, and hope from failed worlds. She buries it for a later iteration, controls its opening and apparent disappearance, and uses it to return impossible route memories to the alliance. (Chapters 472–477 and 480–482)