Seongbin Yu

**Seongbin Yu** (유성빈, *Yoo Seong-bin*) was a major antagonist in *Shotgun Boy*, who was also the first character to show symptoms of monsterization. He was a student at Yeongchan High in Class 1 and the class bully. He got killed by 01.

## Appearance

Seongbin was a tall young man with an lean physical build and had short parted brown hair and light skin. He wears a maroon shirt under his school uniform. He is stated to be attractive by some of his classmates.

After he starts transforming into a monster, Seongbin becomes more muscular and his eyes become prone to bulging. While it's unknown how his complete monster form would've looked like, when he tapped into his monster abilities, his arm became flesh-like in color/texture and his fingernails turned into claws.

## Personality

Seongbin was a charismatic and manipulative student. He is able to remain calm in most situations (when he wants to) and also very smart. Due to his popularity (though most people secretly hate him) and good grades, he is seen as a model student, particularly by people who don't know him personally, like Jayden. He is always being followed around by his group of friends who do what he tells him, especially Chanhyeok and Sanggwon.

Seongbin is a typical arrogant popular student who uses his power to get what he wants. Jongpil refers to him as the textbook definition of a bully. He takes extreme pleasure in reminding others that they are beneath him. He sadistically enjoys the pain he inflicts on others; even engages in to psychologically unnerve whoever he bullies. His favourite victim seems to be Gyuhwan. His classmates are aware of his doing, but he is able to get away with this because of his status as an ace student. He does, however, carry a level-headed and strict demeanour despite his immoral and violent actions. He's also unsympathetic as such showing no remorse for Gyuhwan's sick father.

As the story progresses, his psychotic personality starts to show, notably when he smiled at the dismembered bodies of his classmates. He has been like this even as a kid, as shown when he killed his own brother in his comatose state, even after his brother saved him. This likely stems from him being jealous of him getting their father's attention. Seongbin only truly cares about his own survival. He isn't above sacrificing people who aren't useful and keeping people who may prove useful, even if they are his friends.

He becomes even more unstable when Zero awakens a monsterization tumour on him. He starts to care more about committing acts of violence than his own survival. He is desperate to kill people and makes up excuses for his actions. He ignores the danger he places himself in or the fact that his friends are horrified by his actions when doing so. He is aware of what he is doing but doesn't know why he's like this. When placed in danger, he is still afraid but nevertheless enjoys the *excitement.* When Samshik offers him protection in exchange that he kill Sanggwon, instead of following through, he attacks the monster simply because it called him a loser. Once his monster powers become active, he is enamoured with his new powers and goes on a killing spree.

Underneath his sadistic nature, Seongbin is actually very insecure and cowardly. He has been like this ever since he was a child and killed his brother out of jealousy for getting his father's attention, despite loving his brother. He was forced to live with this guilt and could be the reason why he enjoys inflicting pain on others. He is also likely very lonely because nobody really likes him, including his friends and father.

## Background

As a child, Seongbin desired his father's love. Unfortunately, he only payed attention to his big brother. Eventually, his brother saved him from a truck, sacrificing himself and ending up in a coma. Seongbin used this opportunity to murder him in his sleep.

In high school, Seongbin frequently has bullied Gyuhwan. At one point, he had taken advantage of Gyuhwan's sick father to use his house as a place to drink. Once Shinyeong took notice of Seongbin's bullying ways, she decided to tell him to leave Gyuhwan alone; therefore, she was beaten for "disrespecting" him by his girls. Although, he accepted to leave him alone with the condition that she had become an outcast like him, until he took the courage to punch him in the face and stand up against him.

## Plot

Seongbin first appears in Gyuhwan's dream, bullying him to the point where Gyuhwan snaps and shoots him. He is then seen on the bus to the Yeongchan retreat, telling Gyuhwan saying that he'll be roommates with and Chanhyeok but wants him to switch with Sanggwon. Gyuhwan excitedly says yes, but realizes this was a trap, so Seongbin tells Sanggwon that he changed his mind and gives Gyuhwan a threatening glare. He is present during the Instructor's drill alongside Chanhyeok and Sanggwon, but goes to the nurses office for an "anemia" afterwards. Back in the dorms, he forces Gyuhwan to kill mosquitos for him and Chanhyeok.

The next day, Seongbin and Chanhyeok try to force Gyuhwan to steal liquor for them. Gyuhwan says he doesn't want to because if he gets in trouble, it will put more stress on his sick father. Seongbin doesn't care and threatens Gyuhwan, finally forcing Gyuhwan to submit. However, Seongbin slaps him and calls him a disappointment of a son for selling out his father. Gyuhwan finally calls him out as a piece of trash in a rude way, which deeply angers Seongbin. Gyuhwan immediately jumps out the window and runs, with Seongbin chasing him. Seongbin loses him and gets lost in the woods, causing him to miss the talent show.

Once he makes it back outside the gym, he notices the eerie silence of the talent show. Suddenly, "Hayeong" appears behind him, informing him that a monster attacked the school and killed everyone. He doesn't believe her and wants to check out the gym, dragging "Hayeong" with him, since "he's never seen a dead body." Once he arrives at the gym, he notices multiple dead staff and students. He finds a dying student and asked what happened, to no avail. Inside the dressing room, he finds a flashlight before heading out. On the way out, they see a monster disguised as Mira Han kill two students. The two just barely get out of its sight. They then find a trail of dead students, which Seongbin gives a creepy smile too. They eventually try to escape by using the bridge, but discover that it is broken.

Seongbin runs into Sanggwon and Chanhyeok inside a cave, overhearing that Gyuhwan was hunting for him earlier. It is here, he learns what happened at the retreat. Outside, "Hayeong" notices a mysterious light. Seongbin since Chanhyeok to investigate it. Chanhyeok finds a mysterious child and calls out to the group. They head over and Seongbin calls it a monster. However, this kid/monster uses psychometry to see the time when a young Seongbin killed his big brother. When it asked why he killed his brother, Seongbin denies this and bludgeons it. The others are horrified by this, believing this was a human child (when it's not). Then, Seongbin "coercions" them it was a monster, and the others agree but secretly losing their trust in him.

Later, the group runs into Chayeong Park, who claims to be running from a monster. Seongbin says that she's lying because of seeing Yeongshin's corpse behind her; concluding that she's actually a monster. Seongbin then looks like he's about to kill her, but Chayeong gets away for not convincing him with the truth. The others don't like the way he acted, but he justifies himself by saying that everyone they run into could be a monster (unaware that 03 was listening to their conversation; and when 01 sees this on Three's memories, *he* took an interested in the Monsterization Tumour and told 07 to keep him alive for "that"). Not long after, still giving chase to Chayeong, he begins to have a headache; then, he hears a voice (his soul) inside his head calling him a **murderer** repeatedly; and finally, he starts to have a nosebleed showing the symptoms of monsterization (headache, inner voice talking, nosebleed, and hallucinations; not always in that order). Then, he collapsed and he remembered how and why his big brother, who was the pride of their father, went to coma; however, Zero told his conscience that *he* will "save" Seongbin from his own disease, in addition to save the whole world because *he* came into being to save everyone.

After being unconscious for a certain amount of time, he wakes up unaware of what transpired between Chanhyeok, Sanggwon and finally Hayeong, who suggests that the group starts moving. The group hears something, Seongbin orders Chanhyeok to check again. Chanhyeok is then restrained by Shinyeong, who pokes him with a venomized arrow, so Seongbin threatens her. Shinyeong then asks if he's seen Gyuhwan, which he denies, since he is still alive. Jayden asks that their groups cooperate together but Seongbin arrogantly refuses, saying they could be monsters. Jongpil reprimands his rude behaviour, so he threatens to kill Jongpil, but he is no longer scared of the bully. Shinyeong then asks Sanggwon if he'll cooperate. He agrees, but is threatened to stop by Seongbin, saying he'll kill him if he listens to her, but Sanggwon approaches her anyway which angers him. Jayden requests that they cooperate one more time, but Seongbin can't come to terms with that and asks the other bullies to come back down and part their ways with the group.

While travelling, the group notices notices a group of soldiers leading two students. Seongbin feels something is off, then suddenly the soldiers shoot these students, leading Chanhyeok to scream. One of the soldiers hears this and starts nearing the group, so *Hayeong* suddenly pushes Chanhyeok, using him as bait so they (Seongbin, Sanggwon and *Hayeong*) can get away. Eventually, they take a breather and Seongbin and Sanggwon are shocked by *Hayeong's* ruthless action. Sanggwon then reveals then that she's actually a monster, which leads Samshik to want to kill him for revealing her secret. Samshik then asks Seongbin how she should kill him. Seongbin is shocked but remains calm and notes that she has no intention of killing him, since she went so far to protect her identity. Samshik replies that *something* has awakened in the boy and she's fascinated to see it's results. She offers him protection, but only on the condition he kills Sanggwon. He refuses and attacks her until one shows up and kills Samshik.

One proceeds to attack Seongbin, but he is able to block his tentacle with his newly awakened power. One is fascinated by his new power and the two continue to fight. He has Seongbin restrained but is interrupted when an MM agent tries to shoot him, so he runs off to kill him, giving Seongbin a chance to escape. While running, he has a hallucination of his brother and impales himself because he "no longer feels guilt" for killing him.

He is next seen appearing in front of Sanggwon, who was doubting him. He tells Sanggwon to be quiet as MM-Soldiers pass by. They both hide in the tall grass, Sanggwon asking how Seongbin could see the soldiers from so far away. Sanggwon then asks what happened with "That Monster", Seongbin replying that he'll tell Sanggwon later. Seongbin says his plan to Sanggwon, saying that they'll kill the soldiers and steal their guns.

looks at Seongbin in fear as Seongbin smiles. He flinches and Seongbin notices. Seongbin asks Sanggwon about if he thinks he's a monster, and tells Sanggwon to run up to the soldiers to ask them to help him if he's worrying him. Seongbin commands Sanggwon to stand next to a rotten tree and scream as loud as he can. Sanggwon hesitantly agrees and begins yelling. As the MM-Soldiers hop down to kill Sanggwon, they are each picked off and killed one by one. Sanggwon attempts to run away in fear, but is shot by Seongbin in the shoulder.

Seongbin combed through the guards pockets until he found a magazine clip. However, it is marked green unlike the others he had found. He looks at the bullets, which had a green squishy substance. However, he accidentally spills it onto his hand and as he tries to wave it off, it begins to hurt his hand, making him scream in pain. He quickly runs over to a nearby puddle and washes his hand, the venom turns grey before completely disappearing. Seongbin mentions how it doesn't have normal bullets, and with it, he may be able to kill One, which makes him laugh insanely.

Seongbin murders a bunch of innocent survivors before being confronted by Shinyeong Kang, she asks if Seongbin had killed all the students, and with a smile he says that he killed them. Shinyeong then asks about the people with him, he replies saying that Hayeong was a monster. Seongbin mentions that a 'black haired monster' appeared and killed it. Making Shinyeong remember about One. Seongbin begins to approach Shinyeong, telling her that Chanhyeok was killed by soldiers shooting him in the head. Shinyeong pulls out her bow, telling Seongbin not to take another step closer. Seongbin asks why, and continues approaching asking if its because he's a monster, but then he notices the venom smeared over Shinyeong's wooden arrows. Seongbin continues to approach asking if she can really kill him, she replied saying that Gyuhwan was right, surprising Seongbin.

Shinyeong says that Seongbin was a monster, which he replies saying that he was a monster from the start. But then, Gyuhwan and Zero appear behind him, Gyuhwan pointing his barrel directly as Seongbin saying that he was a monster. Seongbin turns around surprised and says that it has been a while since he had seen Gyuhwan, and it's been a long night. Seongbin then explains about what happened back at the gym when Gyuhwan screamed out Seongbin's name and how he shot the monsters. Gyuhwan says that he wont kill, and if he does kill Seongbin it would be because he lied to Zero which confuses Seongbin. Zero waves at Seongbin, which Seongbin replies saying that he can feel that Zero gave him strength. He asks if Zero is a god, but he doesn't get a reply. Gyuhwan tells Seongbin not to loose himself, but Seongbin replies asking if the shotgun made Gyuhwan cocky.

Seongbin throws his backpack onto the floor and pulls out the recently stolen rifle, surprising Gyuhwan and Shinyeong.

...

## Relationships

### Big brother

He used to love him until their father just paid more attention to his brother than himself.

### Gyuhwan Han

He frequently tormented and bullied Gyuhwan Han on daily basis, for examples he beats him up steals his money and forcing him to do things that might get him in trouble. He Fully takes advantage of the fact that he lives alone not showing a bit of remorse that the fact that Gyuhwan's father is sick. Seongbin became very enraged when Gyuhwan stood up for himself, calling him out on his unsympathetic and cruelty. After hearing what transpired at the gym and what Gyuhwan did he brushed it off, believing that he wouldn't have the courage to shoot a human. After finally meeting each other again he's still down on Gyuhwan and mocks him how he only gets his courage from the shotgun.

### Shinyeong Kang

Shinyeong and Seongbin have always had a very negative relationship as shown she stood up against him for bullying Gyuhwan. He only accepted to leave Gyuhwan alone if he ever stood up again or unless she became his girlfriend, which she denied. Seongbin continued to have his friends beat her and turn her into an outcast. After the variant attack, Seongbin threatens to kill Shinyeong or anyone who joins up with her.

### Chanhyeok Park

Chanhyeok is Seongbin's friend and helps him bullying other students, the exact extent of their friendship is unknown. Seongbin doesn't appear to think highly of him since all he ever does is run his mouth, going as far as forcing him to be monster bait then later threatening him.

### Sanggwon Ahn

Despite their closeness, Sanggwon doesn't like Seongbin, but doesn't say anything because he's too afraid to stand up to him as his right hand. Once he starts too see Seongbin's more psychotic side, his fears only get worse for him and he stops trusting him. Seongbin in turn, only saw Sanggwon as useful due to his bulky nature and likely didn't consider him a real friend either. He is also seemingly unconcerned when Sanggwon's life is in danger. He is aware that Sanggwon has always secret hated him. Eventually, when Sanggwon nearly leaves Seongbin's side to save himself, Seongbin threatens to kill him. Surprisingly, however, when Samshik offers Seongbin protection if he kills Sanggwon, Seongbin refuses and lets Sanggwon run away, though this is partly because Samshik called Seongbin a loser. Sanggwon is not thankful for Seongbin's mercy. Seongbin then orders him to distract MM soldiers for him and Sanggwon regretfully listens to him and runs off, with Seongbin trying to shoot him once for fun.

### Samshik

Samshik is fascinated by Seongbin due to his mysterious tumor. *She* first approaches Seongbin disguised as Hayeong when he's lost in the woods and from then on ally themselves when Samshik informs him of the monster attack. Together, Samshik acts as the shy Hayeong who regretfully goes along with him and his antics. *She* is determined to protect Seongbin at any cost while also keeping *her* identity secret from him. Once *her* identity is finally revealed to him, *she* is angered but then offers him protecting at the cost of killing his friend, Sanggwon.

### Mira Han

They were both bullies. Mira had a crush on him. In turn, he doesn't seem to care much for her.

### 01

The two have a similar nature which 01 finds fascinating. They are both leader-like, cruel savages who will sacrifice other for their own benefit. 01 develops in interest in Seongbin after learning about him. He doesn't want anybody else to kill the boy, but him. When they first meet, he informs the boy that Gyuhwan has already awakened the same thing and he must take his brain now to defeat Gyuhwan, implying this wasn't his original plan. Unlike when interacting with other humans, he is able to casually talk to Seongbin while trying to kill him. He becomes curious and intrigued when Seongbin's is able to break his tentacles. Seongbin want's revenge on 01.

## Equipment

* **Rifle:** It is revealed that Seongbin had stolen a rifle off of one of the MM-Soldiers. He has been shown to have great accuracy with it, managing to shoot Sanggwon with little to no effort. However, he lost the rifle after Gyuhwan shot it out of his hands.
* **Grenade:** It was revealed that Seongbin Yu had stolen a grenade. He unclipped it before attempting to throw it at Gyuhwan.

## Abilities

* **Charisma:** Due to his standing as a school ace, others either look up to him or are afraid of him. With his status, he is able to get away with extreme bullying.
* **Monsterization:** Though he is still incomplete, Seongbin was able to tap into some of his monster abilities. He was able to withstand Samshik's tentacles by bringing focus to his neck and break through 01's tentacles, even when placed in headlock. Also, the substance "Venom" now has an effect on him, seen when he gets some of the substance onto his hand. Due to the monsterization, Seongbin is being engulfed by desire and loosing himself, as stated by Zero. Additionally, Seongbin is able to turn his arms, and hands, into purple claws.

## Gallery

Concept art of Seongbin, Gyuhwan, Shinyeong and 01Seongbin glaring at GyuhwanImaginary Seongbin vs. GyuhwanNot real but still satisfying to seeSeongbin from Gyuhwan's perspectiveA shadowy figure approaches SeongbinSeongbin's group of survivorsZombie SeongbinThreatening his alliesSeongbin catches 01's tentacleSeongbin taping into some of his monster abilitiesSeongbin having a hallucination of his Big BrotherSeongbin impaled himself to rid himself of his hallucination of his brother.Seongbin attempts to flee from Gyuhwan, Shinyeong and Zero.Seongbin and Gyuhwan about to face-off.Seongbin finally getting what he deserves.Seongbin get's killed by 01.
## Trivia

* He is similar to Daon Kim, since they both bullied the respective main character of each franchise.

## References

1. ↑ Ep. 20 (SB)
2. ↑ Ep. 54 (SB)
3. ↑ Ep. 55 (SB)
4. ↑ Ep. 56 (SB)

## Navigation

Variants
Other Variants: Tank-top variant

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