Immortal Regis: 16
165 cm (5'5")
|Guild Mark Location||
Future Leader and Princess of the Demon Clan
|Base of Operations||
Immortal Regis: Chapter 1
Cavalier of the Abyss: Chapter 3
Demon Serin is a young, yet powerful, demon of Chaos and the one responsible for Jae-Hyuk's death. During a battle with a rival demon, she accidentally struck down Jae-Hyuk, when Jae-Hyuk was attempting to bring his ill brother to a hospital. Feeling slightly guilty, she asks him "Do you want to live?", to which Jae-Hyuk answers yes. She brings him back from the dead, transforming him an undead, much to his disbelief, and ends up dragging him back to her world, the world of Chaos.
Serin's transformation of Jae-Hyuk and her supposed betrayal of Jae-Hyuk has served as a catalyst for a majority of events in both Immortal Regis and Cavalier of the Abyss.
Being a demon, most of Serin's clothing follows a Gothic pattern. She is shown in some artwork wearing skull and cross accessories, black lace dresses, or other various forms of dresses ripped up in a bizarre fashion statement.
Serin has long purple hair tied down behind her head and elf-like ears. She has green catlike eyes with black cat lid designs on the sides of her eyes. Serin, as a student, wore a class uniform that consisted of a white long sleeved shirt with a black dress on top of it. She wears black knee-highs held up by garters on her thighs and high heeled shoes. As an adult, she wears a solid black spaghetti-strapped, ripped up, dress, that is longer in the back. She has white bandages on her arms, and black straps wound around her lower legs and crossing over her feet in various areas.
During the flashback arc, she is briefly shown in a Gothic party dress, and later a wedding dress.
Many characters in the series have stated that Serin is very beautiful with even Regis Nex being charmed by her during their first meeting in Earth, a very praiseworthy feat indeed as the Regis is not one who is easily charmed by the opposite gender.
When Serin is initially introduced in Immortal Regis she comes across as a detached cold-hearted warrior, displayed with her lack of emotion on accidentally killing Jae-Hyuk. She shows arrogance in how she addresses Jae-hyuk (Nex) after reviving him and becoming his master. As the story progresses she is shown as kind-hearted and tries to keep her friends safe even while being mortally wounded herself. She has been trained as a warrior to not let emotions override her judgment. However, she is troubled and carries doubts about herself when revealed being the younger sister of Astarote, who was well-known as a powerful warrior and soon-to-be leader of the demon clan. Serin was overlooked as a child for being the weaker sister; after Astarote's death, she is devastated and slowly becomes suicidal. Serin begins to develop feelings for Jae-hyuk and does everything possible to protect him. Serin brings Jae-Hoon to Chaos hoping to give him medical treatment for his frail body as a means of prostration for causing Jae-Hyuk's turn into an undead.
After Jae-Hoon is taken back to Earth, Serin chooses to use her magical abilities to support Abyss from collapsing as a means of condolences. Overall, Serin is a good person and isn't afraid to become the scapegoat if it means saving people's lives. All of her actions in Cavalier of the Abyss are meant to show Serin trying to correct her wrongs.
After her release from prison, Serin claims that she doesn't feel any emotions anymore due to her time in isolation, though this is hinted to be false as she loses control while worrying about Nex and having nightmares when sleeping when remembering that she stabbed him from behind
When Serin was young, she would often read fairy tales. Her favorite story was that of Great Osky and Nex who saved the world. Serin questioned her sister Astarote of the contents of the book and Astarote told her the story might be a prediction of the future.
When Serin's older sister Astarote died, Serin was chosen to become the next leader of the Demon Clan during her time as a student. Some can consider her as a princess of the Demon Clan.
The necromancer responsible for reviving Jae-Hyuk after accidentally striking him down during a duel. She brings him to Chaos with her to attend school. As the story progresses she develops romantic feelings for Jae-Hyuk after admiring his desire to live since she wished to have died instead of her sister Astarote since she was the weaker sibling. After bringing Jae-Hoon to Chaos for treatment, he is possessed by Caladborg. Jae-Hyuk blames her and nearly succeeds in murdering her which she willingly allows him to suffocate her. The two part ways soon after and Serin is saddened by the thoughts of everything being her fault.
An imprisoned Serin is shown screaming when Xix's heart is ripped out by Regis Nex. Her screams intrigue the guards who contemplate taking a peek at The Great Betrayer, but are stopped upon Prince Ninurrta's arrival. After spooking off the guards, a curious Ninurrta manages to open some of the seals leading to her cell and asks her un-rhetorically who she is since nobody speaks of her existence in fear of Regis Nex's anger.
After the fight with Xix, Nex was injured and becomes irritated when his undead abilities do not quickly heal him. He heads off to Serin's chamber and bites her neck to draw blood. As his master, Serin's blood has the ability to heal him instantly. Nex tells Serin's catatonic body that despite her betrayal he would keep her alive for as long as he needs her.
Her father Navarus tries to find a way to free her and makes a contract with Osky to allow him control over a demon, Just, to help him in his search. When Navarus proclaims Just the true heir of Nex; Queen Iffrita becomes distraught since her father was the one who managed to run a pregnant Serin off many years prior.
Shortly after Xix escapes from the castle, Nex journeys to Osky's hideout to confront him about the boy Just being his and Serin's child, Osky taunts Nex by saying that the one who had her imprisoned should be the one to ask Serin even if she couldn't respond in her current predicament.
While people look for kidnapped princess Miya, Just takes Ninurrta to Serin's seal to antagonize him about whether he is truly the son of the Regis since Just claims Serin is still the true love of Nex instead of Iffrita, who proclaimed Nex the father of her unborn child. While they discuss Serin, Xix manages to open a royal seal in Thanatos prison and piques the interest of Nex since only those born of royal blood can undo the seal.
After unlocking the seal, Xix is taken back to the castle where Ninurrta and Xix argue over who is the true heir, Osky shows up and sends them back into the past through the book, Relic of Caladborg, to see how things unfoiled. Xix is the first to see a glimpse of a young Nex telling Serin that he would always protect her.
The book takes them back two years after Immortal Regis where Caladborg is taken to Earth and Nex journeys to find him. During this time, Nex still goes by his human name Jae-Hyuk. Jae-Hyuk has cut all connections with Serin and is adamant in his refusal to discuss any issue relating to her since he believes she abandoned him. In reality, Serin is using her demon powers to help stabilize a tilting Chaos from crashing into Earth below. The machine that drains her energy for this purpose leaves her exhausted. Several of her comrades in this project to save Chaos worry that she is overusing her powers. They all question what made her decide to personally take such a risk. Her newly formed comrade Bi-Hyung comes to understand Serin's hidden motive and questions Serin on whether she will ever forgive herself for Jae-Hyuk's younger brother Jae-Hoon becoming Caladborg after she brought the boy to Chaos for medical treatment. Serin avoids his question and confirms his assumption.
Caladborg grows bored waiting for his brother to find him and decides to make a reappearance in Chaos. Caladborg's helper Nirvana agrees that it's time for his reintroduction into the demon's stone original world and are drawn to Serin's location when she tries to use her powers to close the portal they are using to come into Chaos. Caladborg and Nirvana manage to easily wipe out half of the technical team which leaves Serin to fend for herself. Serin manages to put up a decent fight but trying to fight and stay connected to the machine prove exhausting. Jae-Hyuk is brought to the scene when Bi-Hyung is tossed from Nirvana's attack through the window where Jae-Hyuk and Iffrita were ironically just discussing Serin's situation. Before Bi-Hyung's arrival, Jae-Hyuk learns that Serin continues to send him blood every three days to keep him sane through Iffrita and that he hadn't discovered this because Depore hides the blood out of jealousy. An injured Bi-Hyung pleads for Jae-Hyuk to save Serin, and Jae-Hyuk touched by Serin's kind gesture and thoughtfulness agrees willingly. Jae-Hyuk manages to convince Depore to teleport him to the laboratory where Serin is presently being suffocated by Nirvana. Jae-Hyuk is incensed to find the demon necromancer being injured so intensely. Powering up for an attack, he is stopped by the appearance of Caladborg who is still using the body of Jae-Hoon. Jae-Hyuk still doesn't fully believe Caladborg controls the child's body and is relieved to see his brother. While they are reconnecting his attention is diverted from the small moment of bliss by Serin crying out in pain when the Chao's stabilization machine's cords are yanked out brusquely from her body by Nirvana. Attempting to rush to her aid, Caladborg stops him by asking why that woman's existence is so important to him. Depore grows worried over Caladborg's growing tension and tries to warn Jae-Hyuk but is stopped by Caladborg tearing her body apart. Serin manages to halt his attack on Depore, and Caladborg and Nirvana flee when weariness settles over Caladborg's host.
Serin is taken back to the castle where she is given treatment. Her servant Caesar tends to her, he is outraged when Jae-Hyuk walks into the room asking for an audience with her, but Serin dismisses Caesar. The situation grows awkward with neither knowing how to address the other. Jae-Hyuk begins to speak but is stopped by Serin apologizing for causing his turn into an undead and his brother being taken over by Caladborg. She clings to Jae-Hyuk and admits she was more afraid of never being able to apologize for her actions that brought him pain than being killed by Caladborg in their earlier confrontation. After seeing Serin's distraught and sincerity, Jae-Hyuk forgives her and the two share a passionate kiss.
The two begin to reconcile their relationship, much to the aggravation of Iffrita and Depore. Jae-Hyuk begins to sneak off to meet with the necromancer during his spare time. However, naive Jae-Hyuk is blind to the feelings of his harem as he invites all three women to dinner and innocently wonders why the situation is awkward. Jae-Hyuk asks Serin if she would like to go into town with him later, which the other women decide to invite themselves along. Jae-Hyuk focuses mainly on Serin who seems oblivious to his piqued interest, while the other two try to repeatably gain his attention. The demon princess pauses at one store to admire a rosary choker, which Jae-Hyuk mistakes her for wanting the full attire the choker is displayed on. Despite his stingy habits, he buys her the outfit and is impressed with how well his purchase looks on her. Serin is embarrassed with Jae-Hyuk's appreciative looks, but does not mention out-loud how happy his attention makes her. The four travel to Osky's shop where Serin helps Jae-Hyuk find a book Bi-Hyung needed. In a comical moment, the usually reserved Serin grows excited over a mummy fish corpse and uses some of the demon's clan wealth to purchase the item much to the astonishment of the others.
The party's peaceful shopping excursion is interrupted by a hologram of Caladborg appearing above the city. After introducing himself as King, Caladborg begins to kill the civilians and informs them he will only stop if Serin is murdered since he wishes to protect his precious brother from her. The Chaos citizens turn on her to save themselves, Jae-Hyuk is quick to fend them off and convinces her to flee. The party takes refuge in the Demon Clan's castle, where Serin decides to hand herself over to the mob to prevent more deaths. Everyone refuses and decide to search for Caladborg's hideout to end this once and for all. Before leaving Navarus gives the demon stone, Semek, back to Serin for safe-keeping. Some of Serin and Jae-Hyuk's old classmates, Owen and Infinity, rejoin them to aid in their mission along with Iffrita's cousin, Mikhail.
The company travels to Depore's original chamber which Caladborg had refurbished to fit his liking. Throughout their journey into the newly transformed maze, Jae-Hyuk is told by Hekalroth that Serin will die and it is best for him to accept her fate. Hekalroth continuously reminds him that altering her fate will alter other aspects of the future not for the better. Jae-Hyuk refuses to hear him out and grows more passionate in his quest to stop Caladborg. During their downward descent, the company falls into a trap that places the members into a false dream realm; while the other members dream Serin gets possessed and is mind-controlled by Caladborg. In his own dream, Jae-Hyuk sees a human Serin and Jae-Hoon living together back on Earth in another reality. Realizing its nothing more than a dream he is the first to awaken but not before telling the dream versions of Serin and Jae-Hoon not to worry for he would save them.
Jae-Hyuk tries to confront Caladborg but is ambushed mid-attack by Serin who proves herself a worthy adversary despite his new found strength. He manages to constrict her arms and legs and pleads for her to revert to normal. Unfortunately, his voice still cannot reach her and she uses the opportunity to draw out the demon blade Semek. Using a sneak attack, Serin almost kills him when she activates a partially awakened Semek. Caladborg and Nirvana expect Jae-Hyuk to be forced into using Depore on Serin, and are shell-shocked when Jae-Hyuk allows Serin to stab him with the intention that it may help her break free of the mind-control. Caladborg, still harboring some of Jae-Hoon's conscience doesn't wish for Jae-Hyuk to die and halts Serin's attack. After pushing her aside, Jae-Hyuk tries to surprise attack Caladborg but stops in his attack when Caladborg begins to control Serin into decapitating herself. Caladborg gives Jae-Hyuk two options: will he save Serin or will he save Chaos? To his astonishment, Jae-Hyuk chooses the selfish desire of rescuing Serin over the entire Chaos population. The attack on Chaos is stopped when Caladborg grows increasingly outraged over how important Serin is to Jae-Hyuk, believing that she has replaced him in Jae-Hyuk's heart. After being rescued Serin falls unconscious and does not awaken until Caladborg and Nirvana flee from battle. When she awakens the first thing she sees is Iffrita comforting a distraught Jae-Hyuk which surprises her. Iffrita proposes the plan to make Jae-Hyuk use the Regis room, which controls all the zones of Chaos, and has him become the true Regis. The plan infuriates Shao Shao who attempts striking Iffrita, but is halted by Serin who wishes to hear more details. Since Jae-Hyuk is blood-related to the vessel chosen by Caladborg he is the obvious choice for who could become the Regis. At first, Jae-Hyuk is hesitant but with Serin's quiet encouragement he chooses to accept becoming Regis.
After getting the necessary three acceptances from the descendants of the original Clans who created Chaos (Lycanthrope Owen, Demon Serin, and Serpent Lein) Jae-Hyuk can finally be tested to see if he is approved to be the Regis of Chaos. However, a problem occurs when the system keeps denying him because he lacks a Chaos name. Serin steps forward stating that as his master she is the one qualified in giving him his new Chaos name. She hereby names him Nexus Nex, the name he continues using in the future.
A flashback occurs after granting him his new name to Serin's childhood. The memory shows a young Serin mesmerized by the story of her favorite fairytale based on Osky and the hero Nexus Nex. She asks her older sister Astarote if this person truly existed which Astarote replied she isn't certain it's necessarily a legend, but more of a prophecy.
After naming rechristening him as Nexus Nex the systems supporting Chaos begins falling apart rapidly. The Regis throne accepts Nex as its king, but the power necessary to control the machine proves too powerful for his body to endure and Serin chooses to step in to save him. She uses her magic powers to help take some of the pressure off him. The two of them reflect in a monologue on how everything they're doing is to save one another and how their feelings have changed for one another into love. Serin remembers how she grew to love him based on his desire to live while she herself had originally wanted to commit suicide due to pressure. The two manage to stop Chaos from falling apart and everybody begins rejoicing until realizing Serin has received internal damage. Nex begins to grow hysterical causing Infinity and Lein to pull him aside in order to save the young necromancer. She is spared from death thanks to Lein and Infinity's magic. The party appears relieved and Nex is shown weeping in happiness that she is saved.
The coronation of Nex is shown with everybody bowing in his honor. Serin is shown staring happily at an engagement ring on her finger, she thinks back to the events following after being revived. A smiling Serin is shown sitting on the edge of a cliff with Nex scolding her for being reckless to which she comments that everything turned out all right in the end so there was nothing to worry about. Nex appears annoyed and she promises to never scare him like that again. They share another kiss and at the coronation, she smiles at the memory.
The flashback ends after Serin congratulates Nex and Iffrita asking Mikhail to help her succeed to the throne leaving Xix and company with fewer answers. A traumatized and mentally confused Ninurrta flees at the image of Iffrita promising Mikhail that her first child would be his. Shortly after, the Seal Ceremony is conducted which finds Just as an heir (stolen blood), Ninurrta fleeing, and Xix also passing the test. After Ninurrta cowers at the realization he may not be the true heir and chooses to flee from the scene he runs into a female Night Clan member. The female clan member causes an explosion before kidnapping Ninurrta. After knocking the prince unconscious, the scene changes briefly to Serin in her chamber. The clan member manages to destroy the protective barrier over Merkavah Palace while kidnapping Ninurrta. An annoyed Nex manages to destroy the dragon the kidnapper and Ninurrta are riding on. After the two escape, Nex demands for the barrier to be refixed which Depore explains will be difficult as seeing that Serin is the one who created it. Depore pleads with him to release Serin so she can fix the barrier but Nex refuses.
When Ninurrta awakens from the dragon's collapse, he gets into a small tiff with the girl who brushes his attacks aside. After the two are ambushed by Nex's assassins and manage to fight them off, the girl reveals herself as Siana and asks him to join her. While he is at first hesitant, in the end, he accepts her proposal. Just is overjoyed with the Seal Ceremony's turnout since he never believed Ninurrta would be kidnapped and chose to willingly become a member of the Night Clan. While discussing these turnouts with Navarus, the old man pleads for him to not bring harm to Xix since he is also starting to suspect the boy as Serin's son. Navarus comments about the sorrow Serin carried over Nex and Caladborg's fate. Just believes awakening Serin could lead to more interesting events after listening to Navarus. The demon snake manages to get the Seal to Serin's Chamber to open briefly, but Nex has increased the magic barrier and it quickly shuts after realizing Just is not Nex. Before Just can tamper with the barrier once more Nex appears. Just tries to appear pitiful and claims he only wishes to meet his mother which Nex dismisses since he already suspected Just is not who he claims to be.
Traveling to the Serpent Clan
Nex orders Xix and Just to head to the Serpent Kingdom to protect the other Caladborg fragment since a Night Clan member [Siana] had already broken Merkavah's barrier. While preparing to leave Xix and Yuan get ambushed, but manage to be rescued by Just and the Demon guards. Xix asks why Just would save a rival and Just replies that it's no longer useful to pretend to be the heir. Xix begins to argue over not wishing to be the heir, but is silenced when Just asks if he would like to meet his real mother- Serin. Xix pauses in his argument and blushes over the thought of the demon princess possibly being his real mother.
During the train-ride over to Serpent Kingdom, Xix ponders over whether Serin is truly his mother. Xix and Yuan converse over different matters before getting attacked by the Serpent Guards. After warding off the Serpent guards and meeting the king, Xix begins training. While Xix is training, Siana sneaks into Serpent territory to try awakening the other Caladborg's fragment. She is wounded from dimension jumping and is soon discovered by an intrigued Just, who takes her away to begin torturing her. Xix begins recalling past events with Siana while training and reveals his reason for wishing to grow stronger; while Just knocks Siana unconscious again and begins snooping into her memories.
Xix and Siana's memories: The Banaan Clan Massacre
While shifting through her memories, the readers learn that Xix and Siana grew up together in Banaan Village, Xix was accepted by the village while Siana was considered an outsider. While Xix lives inside the village and is greeted happily by the other villagers, Siana is frowned upon for being the 'witch's daughter.' Siana is often bullied by other children, one of the lead bullies is a girl named Linne who is jealous of Siana for Xix's attachment to her. Linne is smitten with the oblivious boy and one of the girl's many arguments leads to Siana running out of the village sobbing where she accidentally fatefully bumps into none other than Caladborg. During this same time, Xix has been meeting with a traveling Infinity who reveals why the Regis and his guards have been traveling through the territory as of lately. While wary of Caladborg, Siana finds a sense of kinship with him since he understands her loneliness. As the two converse over Siana being different from the other children, Linne stumbles upon the scene. Caladborg is quick to attack her and only stops with Siana's pleading.
He allows Linne to leave, not revealing that his touch is poisonous and taints weaker demons. When Linne returns to the village she quickly discovers to her horror a grotesque infection growing from the same spot where Caladborg had touched her. The crowd has gathered downtown to witness Nex conversing with his guards over private matters. Siana has returned to town during this time to find Xix, when Nex's attention is directed at her she is quick to jump behind Xix. A terrified Linne runs out into the crowd, when she finds Siana she drops the robe covering the infection and demands to know what Siana had done to her. Unfortunately, Linne had been standing right by Nex during this screaming exchange and the moment the robe is dropped he lands a fatal blow on the girl. As Linne falls dead to the ground, Nex proclaims the villagers as traitors and to slaughter the entire village. Within moments, the town is cruelly struck down with Xix and Siana fleeing for their lives.
They manage to make it outside the village when Siana stops, now feeling burdened by the guilt that her interactions with Caladborg had brought this calamity on the town. Xix pleads with her to continue running when he is struck down by a guard and she is soon to follow. As she lies mortally wounded she sees images of herself as an infant being carried by Serin. Serin at this time was fleeing from Nex, as a baby Siana cries Serin comforts her in a doting manner. She sees memories of how Serin revived Nex by giving him her blood and so Siana follows Serin's example and gives Xix some of her blood through a kiss.
After Ninoorut kills himself and is revived as an Undead, revealing himself to be the true son of Nex and Serin, Serin is seen awakening in her cell.
When Caladbolg is about to kill Xix, she interferes with a powerful spell, catching him off-guard.
Serin has joined forces with Caladbolg after her release from prison, though their alliance is an uneasy one as Caladbolg does not fully trust her. She is currently taking care of Ninnorta while waiting for a chance to meet with Nex.
Powers & Abilities
Serin is a powerful warrior with many people in the series praising her strength. Bi-hyung mentioned that she is equal to her sister Demon Astarote if not even stronger. In fact, Caladbolg personally wanted to avoid a confrontation her and had to resort to using Siana as a shield to prevent her from attacking. She is also the only person in the entire series to leave a permanent scar on Regis Nex's body, though this was only done through a surprise attack.
Swordsmanship: In Volume 12, Serin is shown to have powerful swordsmanship, dual-wielding swords and easily defeating Ninurrta.
Necromancy: Serin uses necromancy to revive Jae-hyuk in their first meeting. She is also able to simultaneously raise tens or hundreds of undead to fight for her.
|“||I always wanted to tell you I was sorry. For taking your life, for turning you into an undead, for pulling you into danger. And... for allowing your little brother to become a sacrifice for Caladborg.||”|
—Demon Serin, to Regis Nex
Their relationship is tumultuous since their first meeting. Jae-Hyuk cannot determine his feelings towards the demon since she is both his savior and master; while Serin cannot figure out why she feels so attracted to him simply for his desire to live. The two often get into disagreements that leave Jae-Hyuk proclaiming that he wishes to never have met her, but he still refuses to allow her to die. Serin still offers him aid even after he coldly tells her to never appear before him again. At the end of Immortal Regis, their relationship is strained.
During the flashback in COTA, they are still on awkward terms, but after Serin apologizes they start to work on their relationship with one another. Though Jae-Hoon was originally the only important person to Nex, Serin quickly becomes someone of endearment to him. However, unknown events led to a pregnant Serin betraying Nex and fleeing. Though in current times, she is locked up beneath Nex's castle by his magic that leaves her alive, but unable to do anything besides breathe. People question whether he truly wishes the demon dead or if he cannot bring himself to murder her because he still loves her. Although he angers whenever her name is mentioned, he refuses to allow others to approach her sealed body and still holds on to the demon name Serin gave him-Nexus Nex.
According to Ninurta, despite being extensively tortured and punished for years by Nex living a fate worse than death, Serin is still crying over stabbing Nex from behind and betraying his trust. She deeply loves Nex just as much as Nex love her as similar to how Nex threw away the world for her, she made the same decision to throw away everything for him. Even when she reawakens she spends most of her time thinking about Nex despite having to take care of Ninurta.
Xix may be Serin's son as she was shown giving him to a local village after running away from Nex. She gives Xix the demon stone, Semek. She may have appeared as Yuan in a vision to Xix.
In Chapter 64, the flashback leaves an impression that Xix is Serin's son. However, the father is still unknown. Although in future raws when Siana's fake body is destroyed by Ninurrta Serin grows hysterical and unleashes her powers which catches Nex's attention, when the Regis comes to examine the issue he hears Serin pleading. Drawing closer he is stunned to hear Serin pleading with him to save their "children." Even though the authors have been keeping the heir a secret Serin has been shown several times in flashbacks hiding Xix away from Nex's guards and other characters continually mention if Xix desires meeting his mother. In later raws Xix even manages to momentarily awaken Serin when he removes her blindfold however the seal prevents her from doing much else.
During a flashback scene, one of the names for their child Serin and Nex discuss is "Xix."
In later chapters revelations of Ninoorut actually being an undead who received his horns from a magical implantation and ability to use Noah Clan magic thanks to his undead characteristics causes the readers to question whether Ninoorut is the actual "Xix" while this one is an imposter of sorts. However, no further information and concrete evidence from side characters can fully prove whether Xix is just a random orphan or actually Serin's biological son. However, Caladborg briefly calls Xix the "lost fallen star" during their battle and even wonders whether Serin sees "that thing" as a member of her family considering Xix as a "thing" rather than a person which leaves questions on who and what the young boy is.
It is revealed that Xix is actually a star that Serin made a contract with in order to alter Nex's fate. Xix is not her biological son.
Siana is Serin's daughter and the two share several physical resemblances- same eye coloring and pupil design, along with purple hair and facial features. Siana has also inherited her mother's necromancer abilities. Serin refers to a child she carries as "my daughter" in a flashback. Although Serin is kept highly comatose due to magic the only time she stirs from her "eternal sleep" is whenever Siana is injured. Serin has been shown crying out when she felt her daughter's heart stabbed inside Xix's body and becomes hysterical when Siana's pseudo-heart is stabbed by Ninurrta before the seals restrain her. When Nex comes to examine the problem she pleads with Nex to save their children.
In Chapter 66 and 67 it is revealed that Siana is the daughter of Nex and Serin. Caladborg's wish to use her for this reason also helps prove her lineage. Sadly, after Siana was accidentally murdered by Xix, her true body is being kept safe underground in a laboratory. Several flashbacks from other pivotal characters show different scenes of Serin cradling Siana as she tries to hide her away from Nex's guards. During a flashback scene, one of the names for their child Serin and Nex discuss is "Siana."
In Chapter 131 Serin is fully revived and instantly heads to the battle with Caladborg where she intervenes on the main party's behalf. During the fight Caladborg manipulatively uses Siana as a shield irking Serin who instantly becomes furious and questions whether he is trying to pick a fight with her. Siana is an unknowing third party member during their exchange until Caladborg includes her into the conversation by revealing Serin's identity as Siana's missing mother. Siana is unaware of Caladborg's petty tricks as she tears up and gazes at Serin affectionately apparently pleased to finally meet the woman in her memories. After Serin is freed from her imprisonment, she treats Siana coldly showing little to no concern for her despite her frequent attempts to connect with her, with Siana left wondering if Serin really is her mother.
Serin shows deep loathing and distrust towards Caladbolg. In the past she was even willing to commit suicide in order to kill him. Even after her awakening Serin shows absolutely no affection, care, or respect towards Caladbolg despite the fact that she agreed to joined forces with him. She made it clear that she did not stab Nex for him. The only reason she saved his life was to prevent Nex's death as that was the solution she was told by the prophet.
- "Useless. You are in my domain. I created this area's 'will'. You'll be trapped here forever, boy." - Serin to Ninoorut Noah, in Chapter 72.
- "I always wanted to tell you I was sorry. For taking your life, for turning you into an undead, for pulling you into danger. And...for allowing your little brother to become a sacrifice for Caladborg." - Serin to Regis Nex, in Chapter 29.
- "I'm Alright. More importantly. My baby... I beg you. Please hide him for a short time. I'll definitely come back for him... please. Xix. He's my child." - Serin to Baanan Village chief, in Chapter 64.
- "I just want to meet Nex. I want to speak him. That's more important than these children." - Serin to Caladbolg, in Chapter 132.
- It is very likely that Xix and Siana are Serin's children. They were both carried by Serin when they were babies, and she called them both her children.
- Serin's demon stone, Semek, was given to Xix when she gave him to one of the villagers.
- Serin gave Jae-hyuk the name, Demon Nexus Nex, from her favorite childhood story.
- It hinted that Serin and Nex were the previous couple that saw the dragon up close 10 years ago during the Serpent's Dragon Festival that Yuan and Xix participated in.
- ↑ Cavalier of the Abyss chapter 3, page 13
- ↑ Cavalier of the Abyss chapter 3, page 20
- ↑ Cavalier of the Abyss chapter 5, page 14
- ↑ Cavalier of the Abyss chapter 6, page 22
- ↑ Cavalier of the Abyss chapter 13, page 3
- ↑ Cavalier of the Abyss chapter 17, page 6
- ↑ Cavalier of the Abyss chapter 23, page 18