Do Jaemin

Do Jaemin is a studious high-school student whom Kang Woojin rescues from bullies and later adopts as a younger brother in all but blood. After a vampire's curse forces Jaemin to choose between death and a transformed existence, he becomes a Vampire Lord, an Alandal vassal, and the tactician whose Dimensional Battle victories supply the Points needed to sustain Bibi's Castle.

Biography

A student drawn into dungeons

Jaemin first meets Kang Woojin while being beaten by school bullies who resent the attention he receives from a girl. Woojin saves him, then immediately unsettles him by borrowing all the money in his pocket and asking for his contact information. Jaemin gives him a false number and tries to escape, but their repeated encounters overturn his first impression. He reluctantly lets the homeless, seemingly unstable stranger stay in his studio apartment after deciding that Woojin has had ample opportunity to hurt him and has chosen not to. That judgment begins a relationship built less on easy trust than on Jaemin's ability to recognize actions beneath abrasive behavior. (Chapters 1 and 3–4)

Orphaned with only his older sister Do Jiwon supporting him, Jaemin organizes his life around study. His ambition to work for a major guild is not simply a desire for money or status: he wants stable employment and benefits that will repay Jiwon for functioning as both parent and provider. Woojin's intervention ends the open bullying but isolates Jaemin socially, while Woojin's presence turns his quiet home into a gathering place. Jaemin complains about the noise and impositions, yet he also feeds Bibi, explains modern guild society to Woojin, and refuses excessive repayment once he believes Woojin has already done enough for him. (Chapters 4, 6, 13–14, 19, and 21–23)

Jaemin's duty to Jiwon also governs the opportunity he is willing to take. After learning about a rare healing medicine, he approaches Woojin's new guild because it might repair the injuries that drove Jiwon into seclusion and exhausting factory work. He struggles to ask directly, afraid of exploiting Woojin's generosity, but his motive is clear enough for Woojin to understand. The same self-denial shapes Jaemin's relationship with Lee Soolgi: despite returning her feelings, he treats study and his obligation to Jiwon as reasons to postpone romance, then breaks down after Soolgi leaves to train as an entertainer. His restraint protects his priorities but repeatedly costs him the ordinary life he is working to secure. (Chapters 22 and 26–27)

Woojin eventually uses the salve to restore Jiwon's scarred face. Jaemin is overjoyed to recognize his sister without the coverings she had worn since her accident, though the development also reveals that Woojin and Jiwon have formed a relationship outside Jaemin's knowledge. His gratitude deepens the familial bond that began in his apartment, and he remains one of the few people Woojin trusts for mundane help even after becoming rich and famous: on the eve of Jaemin's college entrance examination, Woojin calls him to settle a taxi dispute, and Jaemin leaves his workbook without demanding an explanation. The student's route toward guild life has become personal allegiance to the man who protected both him and Jiwon. (Chapters 27, 30, 36, and 42)

Vampire vassal and divided loyalties

That allegiance becomes a matter of survival after a vampire bites Jaemin during the Dungeon Break crisis. The curse is already too advanced to remove; if left alone, it will erase his mind and leave a bloodsucking servant. Jaemin explicitly tells Woojin that he wants to live because he has spent his life studying and still has things he wants to do. Woojin can preserve only one victim's identity by killing the responsible vampire and performing a blood succession, and he chooses the boy he calls his little brother. Jaemin is moved by that claim of kinship, but the cure still requires him to confront what survival will cost. (Chapter 51)

Woojin subdues Veymort but refuses to make Jaemin's final decision for him. Trembling and crying, Jaemin must personally stab the vampire's heart before sunrise or die with him. He eventually chooses his own life, and Veymort's blood enters him through the Succession of Blood, transforming a civilian into a true vampire rather than a mindless thrall. The blood tastes ecstatic, while Woojin's immediate killing of another cursed victim shows Jaemin the ruthless choices surrounding his new existence. He does not adopt Woojin's moral certainty overnight; he closes his eyes, grieves the feeling that his humanity has been shed, and enters Alandal because sunlight will now kill him. (Chapter 52)

Inside the Dimensional Domain, Jaemin's first enemy is his own hunger. He isolates himself rather than risk attacking residents, can barely keep from biting Woojin, and drinks a few offered drops with the desperation of a starving person. He simultaneously wants to die and wants to live, and he cannot yet face Jiwon as a monster. Over the Domain's accelerated time, he begins hunting with Kiba so that he will not lose control around refugees, reads about other Domains, and accepts Woojin's reframing of him as an unusual Awakened rather than a discarded human. That interpretation does not erase the dissonance, but it gives Jaemin a role from which he can begin rebuilding his life. (Chapters 53–54 and 57)

Adaptation allows Jaemin to reunite with the people he feared losing. He drinks purchased blood at Bibi's café, meets Jiwon while still pale and gaunt, and returns to Earth to watch Soolgi perform. When monsters attack the broadcasting station, he searches for her, protects the trapped civilians until severe wounds and hunger push him toward collapse, and refuses to feed on Soolgi despite needing blood to heal. She places her wrist in his mouth by choice; her blood closes his injuries, and her embrace after he recoils gives him proof that someone besides Woojin and Jiwon can know what he is and still trust him. The rescue reconnects his transformed body to the human relationships that motivate him. (Chapters 62–65)

Woojin then makes Jaemin a strategic adviser and places him in a mixed party whose growth depends on Jaemin becoming a reliable front-line fighter. Monster blood grants explosive speed, strength, and healing, but his first major surge on Jaku sends him into a frenzy in which he attacks without defense and even tries to bite Baek Jongdo. Jaemin accepts that his overconfidence and thirst helped trap the party, yet he does not surrender to despair; unable to benefit from Melody's holy healing, he drinks from wounded Orcs, uses his claws and speed to hold the line, and keeps fighting until help arrives. The failure teaches him that power cannot substitute for control or responsibility to teammates. (Chapters 64–65 and 69–71)

Alandal's tactician

Feeling the ceiling imposed by Veymort's low-ranked blood, Jaemin asks Woojin to lend him an enormous number of Points for a Vampire Lord's Heart. He is embarrassed to request more after everything Woojin has done, but his recent failure has made the need for greater strength concrete: Woojin cannot always remain beside Alandal, and Jaemin wants the capacity to protect others in his absence. Woojin buys Count Kiet's Heart outright, and Jaemin accepts it with the intention of repaying the gift through service. The second Blood Ritual grants a Count's rank, greatly expands his growth potential, and qualifies him to found and command a vampire clan. (Chapter 72)

Jaemin's new blood changes both his capability and his temptations. On Jaku he turns monsters and a dying human warrior into blood dependents, senses their fear, hatred, and hunger, and experiences a troubling thrill when his first clan member kneels. His underlings obey but remain potential challengers if he appears weak, forcing authority and danger into the same bond. Early confidence leads him to assault a Colony too aggressively, and Woojin destroys his hastily gathered force to demonstrate how little raw numbers mean without command. Jaemin responds by becoming slower and more methodical: he works with his party to isolate a Dimensional Lord, clears the leaderless Colony, and feeds on defeated monsters without the earlier loss of reason. (Chapters 73 and 75)

As Alandal opens its counteroffensive on Alphen, Jaemin becomes one of the few Earth vassals strong enough to join Woojin's vanguard. He can fly, conceal himself, access the Dimensional Storage, and communicate mentally with Woojin across vast distances. Those privileges become logistical responsibilities as well as combat tools: he supplies food to coalition survivors, tracks enemy lords, delivers intelligence, and is appointed Alandal's tactician. His instinct is to analyze danger rather than assume Woojin will solve it; when prophecy implies catastrophe and when an enemy army gathers near Sauraus Mountain, Jaemin presses for contingency planning even as stronger personalities dismiss the threat. (Chapters 76–82)

The defense of Sauraus Mountain tests that caution. Jaemin initially reassures the coalition that Woojin can return through a Return Portal Marble, only to discover that the absence of Alphen's Code prevents the item from functioning there. With Woojin unreachable or delayed, Jaemin becomes the command link for frightened heroes, scouts the advancing Dimensional Lords as a bat swarm, sends orders through smaller bats, and relays Woojin's messages when contact resumes. He still depends emotionally on Woojin's promised arrival, but he remains at his post after the deadline passes and participates in the retreat that preserves the coalition until Woojin returns. His tactical role is no longer a game played safely from a chair; it carries the lives of people who treat “Count Jaemin” as their commander. (Chapters 81–84)

After returning to Earth, Jaemin's caution is redirected toward Kang Sooah. Woojin orders him to protect her at any cost, and Jaemin remains close as her bodyguard, resists proposals he considers needlessly dangerous, and relays information when Earth's completed Synchronization begins the wider catastrophe. By this stage the sunlight that once threatened instant death no longer affects him, and he can control his thirst, but his experience on Alphen has made him more wary rather than reckless. Protecting Sooah connects the obligations that defined him as a student—guarding family through disciplined effort—to his new responsibilities as an Alandal vassal. (Chapters 84 and 87–89)

Jaemin's most consequential final contribution is sustained away from the visible battlefield. Seated as tactician, he treats Dimensional Battles as strategic games, repeatedly defeats opposing Domains, climbs the Rankings, and amasses Points. When Woojin disappears, Bibi's Castle must spend those Points both to maintain tens of thousands of Undead and to defend itself. Jaemin continues battling without rest while Black Armor wears down the fortress; the Energy from one of his victories reaches Bibi in time for her to reactivate its barrier during the final crash. His work does not defeat the attacker directly, but it keeps Alandal's army and civilians alive long enough for Woojin to return. (Chapters 89–91 and 93)

Appearance and personality

Jaemin is already notably handsome as a human, and that appearance contributes to the jealousy behind his school bullying. Vampirism makes him paler and even more striking, enough that strangers at an idol recording mistake him for a prospective celebrity. During his early return to Earth he wears dark clothing and sunglasses to protect himself from daylight, while later blood succession gives him a more imposing presence recognized on Alphen as that of a Count. The corpus describes the change in pallor, presence, eyes, fangs, and claws more consistently than it gives fixed details such as height or hairstyle. (Chapters 1, 4, 62–63, 73, and 81)

As a student, Jaemin is cautious, diligent, and painfully aware of what Jiwon sacrifices for him. He can be timid in confrontation and embarrassed by attention, but he is neither passive nor selfish: he studies with intense focus, tries to keep Soolgi safe without exploiting her affection, and opens his home to Woojin after judging that the apparent danger is not malicious. His tendency to worry survives every increase in power. On Alphen it becomes useful skepticism, driving him to take prophecy, enemy movements, deadlines, and evacuation plans seriously when his allies prefer confidence. (Chapters 1, 4, 6, 22, 26, and 79–82)

Vampirism introduces desires that conflict with that temperament. Blood brings ecstasy, combat power, and at times pride in the fear of his dependents; uncontrolled feeding can turn him berserk. Jaemin is ashamed of these responses, yet he does not solve the conflict by pretending they do not exist. He hunts to manage his thirst, accepts blood when necessary, practices strategy, and gradually drinks from defeated monsters without losing himself. His development is therefore not a return to his old innocence but the creation of discipline strong enough to use a dangerous nature in service of relationships he still values. (Chapters 52–53, 57, 62, 64, 69–75, and 89)

Abilities and class

Jaemin begins as an ordinary civilian and becomes a vampire through two successive blood inheritances. His first succession preserves his mind and grants the abilities of Veymort's line; the second makes him a Vampire Lord of Count rank, breaks the earlier limit on his growth, and adds command over blood relations. His separate appointment as Alandal's tactician gives him access to Domain communication, storage, and Dimensional Battles.

Succession of Blood and vampire physiology

Veymort's bite first places Jaemin under a curse that will kill his human identity and produce a mindless servant after one night. Killing Veymort through the heart before sunrise triggers the Succession of Blood: the dead vampire's blood flows into Jaemin, passes down its power, and preserves Jaemin as a true vampire. The transformation immediately increases his level and physical potential, but it also creates a dependence on blood and a lethal sensitivity to sunlight. Woojin cannot reverse the curse; the ritual is a choice between transformed survival and death, not a restoration of Jaemin's original body. (Chapters 51–52)

Blood functions as food, medicine, and a growth medium. Drinking even a few drops suppresses acute hunger, while a sustained feeding can close deep wounds in seconds. Monster blood contributes portions of physical ability, Stats, and regenerative improvement, letting Jaemin accelerate beyond the progression of ordinary Awakened. The transfer's duration and magnitude are not precisely quantified, and the source does not establish that every trait of every target can be copied. Holy healing is incompatible with his undead-like nature, leaving blood or non-holy recovery magic as his demonstrated alternatives. (Chapters 53, 62, 64, 69–71, and 75)

The same mechanism is dangerous. Fresh blood produces intense pleasure and can increase his thirst faster than his judgment develops. After feeding on powerful monsters, Jaemin gains exceptional speed and strength but can enter a red-eyed frenzy, disregard defense, outrun his party, and bite an ally who tries to restrain him. Tough skin can break his fangs, wary enemies can still injure him, and regeneration depends on access to blood rather than making him invulnerable. Training and the Count's succession improve his control; by Chapter 89 he explicitly states that he has escaped the curse of the sun and can manage his thirst, though the corpus does not identify a separate technique responsible beyond his inherited higher rank. (Chapters 64 and 69–72, 75–76, and 89)

Blood Ritual and Vampire Lordship

Veymort's low-ranked blood imposes a cap on Jaemin's development, so he undergoes a second Blood Ritual with Count Kiet's still-beating heart. Blood fog from the heart enters his body and passes on the previous owner's Count rank. The immediate sensation is subtle, but the ritual multiplies his growth potential and qualifies him as a Vampire Lord. This is a permanent inheritance purchased with Domain Points, not a temporary combat enhancement, and Jaemin thereafter develops through further feeding and battle. (Chapter 72)

Count rank grants Blood Relation, allowing Jaemin to found a clan and command lower vampires. By placing his own blood on a dying warrior's lips, he transforms the man through a violent bat-like reconstruction that restores lost limbs and creates a member of Jaemin's blood family. He can also turn defeated monsters into blood-dependent troops. The bond transmits his subordinate's fear, hatred, and thirst to him and compels obedience, but it does not create affection or perfect loyalty: his followers may challenge and consume him if he shows weakness. His first army is destroyed quickly by Woojin's forces, demonstrating that creation and nominal command do not substitute for tactics. (Chapters 72–73)

Physical combat, transformation, and reconnaissance

Vampirism gives Jaemin enhanced strength, speed, durability, sight, fangs, claws, and regeneration. Even before Count rank, he can punch aside a panther capable of bending steel and kill it with a kick; after drinking monster blood, he moves fast enough to blur and cuts Orc throats with claws used like blades. His preferred approach develops from reckless frontal attacks into rapid strikes coordinated with tougher allies. Because his healing is blood-dependent and holy support cannot restore him, his effectiveness falls when he is isolated from viable targets or loses control of his feeding. (Chapters 62–64 and 69–71)

Jaemin can disperse into a cloud of bats, reform his body elsewhere, and fly as a bat. He uses this transformation for aerial travel, escape, concealment, and scouting rather than merely as a visual effect. After inheriting Count blood, his camouflage is compared to Ggaebi's, he can approach through darkness without being noticed, and he sends smaller flocks outward to carry orders across a base. The source shows these applications but does not define maximum range, duration, or whether every bat must survive for him to reform. (Chapters 73, 76–77, and 82)

Domain tactician and Dimensional Battles

As Woojin's appointed strategic adviser and later tactician, Jaemin can communicate with him by will even across Dimensions, subject to interruptions when Woojin is inside certain dungeons or otherwise unreachable. He receives privileges to access the Dimensional Storage, deposits loot, withdraws provisions, and uses that authority to feed coalition survivors. These are delegated Domain permissions rather than innate vampire powers, and they depend on Woojin maintaining Jaemin's vassal role. (Chapters 64, 69, 73, 78, and 81–82)

From the tactician's chair, Jaemin acts as Woojin's proxy in Dimensional Battles. The system lets him direct troops, production, technology, and attacks in a strategic contest between Domains; victories earn Protection Periods, plunder, Rankings, and Points. His study habits and grasp of game-like strategy make him more proficient than Bibi, whom he trains through mock battles. By the latest chapters he can fight many matches consecutively without obvious physical exhaustion, but the corpus does not establish that his record is literally flawless across all time. His accumulated Points remain finite and are consumed rapidly when Bibi's Castle must support both its barrier and Woojin's Undead Army. (Chapters 61–62, 69–72, 73, 89–91, and 93)

Power progression

Relationships

• Kang Woojin: Jaemin progresses from fearing Woojin as an unstable stranger to treating him as an older brother and master. Woojin protects him from bullies, lives in his home, heals Jiwon, preserves Jaemin's mind through vampirism, and funds his rise to Count. In return, Jaemin entrusts his life and growth to Woojin, serves as his tactician, and keeps Alandal supplied during Woojin's disappearance, while retaining enough independent judgment to worry about plans Woojin treats casually. (Chapters 1–6, 26–30, 42, 51–57, 69–73, and 81–93)
• Do Jiwon: Jiwon is Jaemin's sister, guardian, and original reason for pursuing a guild career. He studies to repay her sacrifices and seeks a rare healing medicine for her injuries. His greatest early fear as a vampire is facing her as a monster, but their reunion helps him reconnect his changed life to his family. (Chapters 3–6, 14, 21–22, 26–27, 30, 51, 53–54, and 62)
• Lee Soolgi: Jaemin initially suppresses his feelings for Soolgi because study and Jiwon's welfare come first. After Soolgi becomes an entertainer, he searches for and protects her during a Dungeon Break. Her voluntary blood and acceptance restore his body and reassure him that vampirism has not made intimacy or trust impossible. (Chapters 6, 26, and 62–65)
• Bibi: Bibi shelters Jaemin in the Domain, helps rescue him from the broadcasting station, and calls him her student. Strategically, the relationship reverses: Jaemin teaches her through mock Dimensional Battles and later earns the Points she uses to sustain Bibi's Castle and its barrier. (Chapters 53, 61–65, and 93)
• Hong Sunggoo: Sunggoo and Jaemin become the principal Earth fighters in Woojin's Alphen vanguard. Jaemin respects Sunggoo's endurance and trust in Woojin, warns when that confidence becomes reckless, and supports him through the defense of Sauraus Mountain. Their contrasting caution and optimism help the expedition function under pressure. (Chapters 65, 71, and 75–83)
• Kang Sooah: After Alphen makes Jaemin more cautious, Woojin assigns him to protect Sooah. Jaemin remains beside her on Bibi's Castle, notices when Earth's god begins acting through her, and resists unnecessary risks because keeping her safe is an explicit order rather than an abstract duty. (Chapters 84 and 87–89)

Items

• Return Portal Marble: Jaemin identifies Woojin's marble as the planned emergency route back to the Alphen Colony while serving as tactician. The plan fails because Woojin lacks Alphen's Code, establishing a planetary restriction on the marble; the corpus does not show Jaemin personally owning or carrying it. (Chapters 81–82)