- "I must search for the next 'Mem Aleph' for the sake of having my ambitions granted."
- ―Seth Twiright[src]
Seth Twiright, later known as the Demon of Wrath, was a scientist from the Magic Kingdom Levianta and the father of all HERs in the Third Period. Originally one of the surviving earthlings, he escaped from the Sin and reincarnated as a human. Afterward, Seth experimented with the creation of ghoul children and vessels of sin to increase the number of HERs in the world, eventually taking over Project 'Ma' for his ambition. Following the Levianta Catastrophe, Seth reincarnated again as the Demon of Wrath.
- "You've still forgotten, just like the other demons and spirits. Shame the only one who seems to recall the Second Period is me."
- ―Seth to Gumillia[src]
Seth Twiright was created in the Second Period as one of many sentient man-made masks. Sometime after his creation, he became a renowned physicist and one of the inventors of the Black Box device. While the Second Period began to fall due to the rampant spread of Hereditary Evil Raiser Syndrome, Seth used Black Box to prove the existence of parallel worlds. He later revised his design to create Black Box Type S, which allowed the movement of spirit data between parallel worlds. Having become an HER himself, Seth began plotting to sneak aboard the spaceship the Climb One, one of several spaceships which were to travel to an inhabitable planet for the purposes of repopulating humanity.
When a colleague, Levia Barisol, consulted Seth regarding her impulsive desire to kill, he suggested she kill her counterpart from an alternate reality to possibly destroy the malice, hoping to have her be consumed by her murderous desire and so he could take her place on Climb One. After the plot failed, Seth faked his own suicide, killed one of the crewmembers, and took their place on the ship. With seventy-one other scientists, he successfully escaped the world's destruction. When the Climb One lost contact with its fellow spaceships and the crew's plan was to create a new species in the image of earthlings, Seth plotted to sabotage the plan.
Once the ship found a new planet to inhabit and the new world, as well as its species, was being designed, Seth created the laboratory Lunaca Labora equipped with the advanced technology of earth. As the humans that the earthlings created were stored there, Seth created his own artificial human body and put it in cold storage among them. He then contaminated the new species so that it had a chance to develop HER Syndrome and instigated the deaths of sixty-two members of the crew of the Climb One. Afterwards, he was discovered; with his original body destroyed, Seth beamed his spirit data into his body in cold storage and awoke in Lunaca Labora.
Meanwhile, Seth having infected Levia and other crewmembers with HER Syndrome, the crew of the Climb One got into a fight and the ship crashed, killing all the earthlings and leaving only their spirit data. With the HER infected Levia, Behemo, Marie, Salem, Vlad, Gilles, and Rahab all trapped in the crashed Climb One, Seth came in contact with them and plotted with them to destroy the world that the earthlings had set out to create. In the meantime, the humans of the new world, the Third Period, began creating their own civilizations; discovering Lunaca Labora, some of the humans used its technology to found the powerful Magic Kingdom Levianta. Discovering the Climb One, they determined it a holy relic, the ark "Sin".
- "You aren't exactly human either, right? Seth made ghoul children by imitating me."
- ―Behemo to Irina Clockworker[src]
Under Alice Merry-Go-Round's orders, Seth became a prominent scientist in the Magic Kingdom Levianta, using his knowledge as a former earthling to experiment with Hereditary Evil Raiser Syndrome. Around the BT 020s, Seth developed a method of creating artificial human HERs based on Behemo's original method for creating human bodies. Using his own DNA, Seth created and released his first two "ghoul children" into the world, Pale Noël and Kiril Clockworker, who were identical to him. Once Pale gained notoriety as leader of the criminal organization Apocalypse, Seth explained away their resemblance to each other by claiming they were separated twin brothers.
Deciding it was too risky to make ghoul children with his face, Seth developed a new method of creating them. In BT 022, he developed another child, a girl, and implanted seeds of malice in her to create a new HER; he named the child "Meta Salmhofer." Seth continued the creation of ghoul children through seeds of malice implantation, allowing them to wreak havoc upon Levianta in the succeeding years. In BT 004, Seth successfully created his twelfth ghoul child, inputting "Irina Clockworker" as Kiril's little sister.
At some point, Seth collaborated with the Senate to take Adam Moonlit's mother, Queen Alice, away from him. Seth later took vested interested in Project 'Ma' and its goal to have a mother give birth to the vessel bodies of Levia and Behemo for their reincarnation into the world as humans. After the failure of the first project, Seth was appointed head of the second and selected Meta Salmhofer as the new candidate due to her unique magical power. With the cooperation of the Leviantan Senate, Seth successfully captured Meta and convinced her to become his test subject in exchange for a pardon.
Afterwards, Seth presided over Meta's inoculation with the seeds of god, sabotaging them to ensure the babies would develop HER Syndrome. Following the successful births of Hänsel and Gretel on December 27, EC 0, Meta fled with the twins and a search for the escaped mother began. During the process, Seth's past experiments creating artificial humans were discovered and he was dismissed from the royal institute.
During this time, Seth began creating devices that would affect humans to behave similarly to Hereditary Evil Raisers, including a Jakoku styled sword and a golden key he dubbed "Grim the End". He also developed a new device capable of drawing the affected into one's inner psychological world, installing a smaller Black Box Type S into the heart of a stuffed red cat. Among his creations was also a "boy" that could create untold destruction on the Third Period; not wishing to destroy the world, Seth sealed the "boy" away in Lunaca Labora. In time, Seth was readmitted to Project 'Ma' after successive projects failed to produce twins.
While heading the seventh project in EC 013, Seth met Kiril Clockworker and learned he had been cured of being a HER. When his creation noticed their resemblance, Seth claimed to be a ghoul child like him, convincing Kiril he was also cured and trying to save the country with the project. After Irina Clockworker, Elluka Chirclatia, Ly Li, and Milky Eights were selected as potential candidates for the seventh project, Seth influenced Irina to kill the other three women; once her rivals were dead, Seth had Irina selected to be the new Ma by default, implanting her with the seeds of god at the royal institute.
When the Magic Kingdom was destroyed around six months later, Seth was caught in the blast; although severely burned, he managed to survive and took the stuffed red cat to the limbless and dying Irina. Bringing her into Lunaca Labora, he transferred Irina's spirit data into the stuffed cat. Later, he departed from the laboratory after commanding Irina to continue the experiment, his human body dying of its injuries.
Mantle of Wrath
- "Surprisingly, he had been the Demon of Wrath. After he died as a human being, he probably cleverly slipped in when the twin gods began creating the vessels of sin—no, you'd think it was his suggestion for the other demons as well, perhaps..."
- ―Irina Clockworker[src]
Following his death, Seth was reincarnated as a demon as part of Hänsel and Gretel's Re_birthday in EC 014, becoming the "Demon of Wrath" inhabiting Grim the End and still retaining his former memories. Afterwards, the demons and their vessels of sin were scattered across the world, armed with the knowledge of the sun god's rules for demons.
Later on, the soul of Adam Moonlit joined Seth in the golden key and leeched off his vessel and power. As time progressed, Seth allowed Adam to act in his place as the "Demon of Wrath", watching while Adam contracted with humans consumed by hatred and rage. His viewings included Count Karchess Crim using the key in EC 137, Prince Carlos Marlon ingesting shavings from the key in the fourth century EC, Yvette using the key in EC 477, and Clarith almost contracting with wrath in EC 505. Sometime after, Grim the End fell into the possession of the Blankenheim Family.
After Grim the End was acquired by Irina in the latter half of EC 608, Seth heard out her suspicions about whether Elluka Clockworker was really the resurrected Elluka Chirclatia. In response, he readily explained everything to her about the gods, the rules and mechanics of the world, and how reincarnation typically suppresses a soul's memories, leading Irina to realize that Elluka Clockworker was a reincarnated Levia, accompanied by Behemo, in Elluka's body. Seth's vessel later was stored in Irina's treasury and he watched it come under use by Gatt Coulomb and, later, the reincarnation of Hänsel Lemy Abelard.
On January 29, EC 611, Gatt took the vessel and used it to ambush Elluka Clockworker's carriage en route to Merrigod Plateau. Once he was defeated, the vessel fell into the hands of her apprentice, Gumillia; Seth quickly recognized Gumillia as one of the earthlings whose death he instigated, who had been reincarnated as a forest spirit and then into a human.
Duel of Merrigod Plateau
- "Feels like the first time I've tried being the Demon of Wrath but it's quite difficult, isn't it?"
- ―Seth to Adam[src]
The next day, Seth watched while Elluka and Gumillia confronted Irina at Pale Noël's tomb in Merrigod Plateau, battling her before Lemy arrived. As he fight began again, the four were locked in a stalemate of Elluka against Irina and Gumillia against Lemy, Lemy unable to be defeated due to his contract with the Glass of Conchita. After two hours of fighting, Seth became exasperated with the duel; learning that Adam couldn't act as the Demon of Wrath because Gumillia lacked hate, Seth decided to act on his own for once and called out telepathically to the exhausted Gumillia.
As Gumillia continued to fight Lemy, Seth bantered back and forth with her as he tried to persuade her to trust him, additionally pointing out that only a contractor could kill another contractor. When Gumillia refused to contract with him, Seth offered to allow her a temporary contract to resolve the fight. He continually badgered her, pointing out her lack of other options and how simple it would be to turn Grim the End into a bullet for her purposes. Eventually, he convinced her to accept his temporary contract; lending his power to Gumillia, he watched her turn the golden key into a bullet and shoot Lemy in the head with it.
While he relinquished his contract, Seth noted how the Demon of Gluttony had absorbed Lemy's soul into the glass. He chatted with Adam about the seeming outcome of the duel before Gumillia tried to speak with him again; hearing her ask for his name, he revealed his identity to her as "Seth Twiright." Once Irina activated her heart's Black Box Type S, Gumillia was caught in the blast and transported into Levia's inner psychological world, leaving Grim the End and Seth behind. After the Demon of Gluttony opened a portal into the mental world and clashed her Worldeater with Levia and Irina's magic, the blast blew Seth and Adam out of the golden key.
Meeting in Hell
- "Honestly, I'm in quite the mess..."
After the blast, Seth ended up in the Hellish Yard in his mask form. He was shortly after found before the bridge leading into the Heavenly Yard by Behemo, who started stomping on him. The two were joined by Gumillia; after Behemo gave the mask to Gumillia, Seth revealed to her how the mask was his true form. The three of them discussed how the duel had brought them into this situation, with Seth speculating on what had happened to Adam since the blast. When Behemo suggested they visit Held in the Heavenly Yard, Seth elected to be left behind in hell; Behemo tossed him back to Gumillia, who was unable to enter Heaven due to still being alive.
Amused, Seth watched Gumillia's conversation with Behemo, in the process learning that there was a miasma permeating the Hellish Yard which would slowly drive them insane. Although still amused, when Gumillia noted he'd also be affected by the miasma Seth determined that he would research a means to stop it. He then requested that Gumillia be his limbs for him by putting him on. Convincing her to trust him and assuring that he couldn't take over her body, Seth described his abilities as the mask to see in the dark and read minds while Gumillia put him on. The two of them then went off to begin looking for research materials.
In the intervening centuries, Gumillia became the Master of the Hellish Yard and Seth aided her in setting up the systems in the Hellish Yard that would allow her to sort the good and bad souls. After the soul of Giyara ended up in the Hellish Yard in EC 842, Seth noted how it had been caused by a malfunction from one of their systems; he watched as she granted the monk a wish in compensation and set him on his way. Shortly after, Seth became amused when Gumillia discussed with him how she'd seen that Allen Avadonia, who was meant to be confined in Black Box, was nonetheless reincarnated onto the ground world due to Behemo's interference. At some point, Seth, having continued his research into parallel worlds since arriving in hell, created Neo Black Box. Asking Gumillia to test it as his guinea pig, he was met with her refusal.
A Very Amazing Octopus
After the birth of Nemesis Sudou, who was a reincarnation of Levia, Gumillia sent Seth Twiright to the ground world inside Grim the End. Instructed to keep Nemesis alive, Seth approached the young child while she lived in an old house in the Millennium Tree Forest, abandoned by her mother Ma. Making Grim the End shapeshift into a ziz tiama octopus, Seth handed himself over to Nemesis and the girl adopted him under the mistaken assumption he was a present from her mother, Seth deciding to let her believe the notion although her mother had in truth abandoned her.
That night, he approached Nemesis in a dream and tricked her into making a contract with him, using it to lend his power to Nemesis and making her unable to die. From that day forward, Seth lived with Nemesis as her pet, "Ziz-san". Over time, Nemesis learned how to give "Ziz-san" orders telepathically. In EC 978, after she had joined the gang Zeus, Seth accompanied Nemesis and Narcissus to a bar for the rival gang Hades. Once instructed, Seth used his tentacles to restrain all of the Hades members while Nemesis questioned their leader over the death of Zeus member Dio Ames.After Nemesis instructed him to release his opponents, she carried Seth home and brought him to the Lake of Amusement to stay for a while. Several days later, Seth accompanied Nemesis and the rest of Zeus to a port city while a separate group tried to assassinate Midas Touch on the S.S. Titanis. After Zeus botched the assassination attempt, Seth sank the entire ship on Nemesis' orders, killing everyone onboard. He then retrieved the Clockworker's Doll from the wreckage and gave it to his young master.
Much later, when Nemesis was being pursued for the sinking of the Titanis, the pool that Seth normally stayed in was frozen over by Nikolay Tolle and he was incapacitated while the girl was taken into custody. By the winter of EC 982 he had found Nemesis again in Rolled, his power keeping her alive as she tried to commit suicide after shooting her lover. Using the key to shapeshift into his human form, Seth disposed of the body of her lover and then met with Nemesis after she came to, having her come inside from the snow to talk.
While he talked with Nemesis, Seth told her the truth of what he was, how he could transform using Grim the End, and how she'd contracted with him; during this, to protect Nemesis' emotional state, he maintained the lie that her mother had unwittingly picked him out as a Christmas gift. After asking Nemesis what she next intended, and hearing that she had planned to die, Seth urged her to live instead; he transformed Grim the End into his mask form and several golden bullets. Seth then offered Nemesis a choice: either use the bullets to kill the people she considered truly evil, or shoot herself with them.
The Mask of Nemesis
Nemesis chose to live, and Seth from then on accompanied her as she quickly became entangled with the Tasan Party and USE politics. When the Leviantan Civil War erupted in August of EC 983, Nemesis wore Seth while he was in his mask form and he lent his powers to her, aiding her as she hunted down and then killed General Tony Ausdin outside his own mansion. When Nemesis spared Tony's pregnant wife and son afterwards, Seth criticized the decision, citing that the son may come back for revenge one day. Soon after, Nemesis wore Seth to Gallerian's mansion, Seth speculating to her the possible reasons the mansion was mysteriously found on fire.
Protecting Nemesis as she entered the burning mansion, he stood by as she found Gallerian talking to a doll and explained how it, the Clockworker's Doll, was another demonic vessel like Grim the End. Seth then watched approvingly as Nemesis, loading her gun with golden bullets, confronted Gallerian at gunpoint. As Nemesis began to have doubts over killing Gallerian, Seth pointed out how with his power she could get him out of the mansion unscathed and hand him over to the militia's custody. Not long after, however, Nemesis found Gallerian unable to repent for his crimes and shot him with Grim the End, killing him.
Years later, Nemesis would use another golden bullet to shoot Nikolay Tolle while he lay on his deathbed. After Nemesis became the dictator of Elphegort, Seth still accompanied her as "Ziz-san", staying in a tank at the Tasan Party's headquarters. At some point during the war that broke out over the world, Seth reluctantly helped Nemesis to revive the "boy" of destruction that he had sealed away, Nemesis using it as a basis for a new weapon called "Punishment". After Nemesis used two more golden bullets to kill Bruno and then Ma, she fired Punishment over the entire world in EC 999, destroying all life in the Third Period.
- "I don't know that woman's intentions though. Whether they're her intentions or she's being manipulated by the mask..."
- ―Hänsel regarding the Master of the Hellish Yard[src]
By the time that the destroyed Third Period had subsequently merged with the Hellish Yard, Seth had left his vessel and returned to being worn by the Master of the Hellish Yard. Nonetheless he maintained his contract with Nemesis even as her soul was split off from her body. Her physical body, kept alive by the demonic magic, began instinctively trying to reenact the destruction of the Third Period.
Meanwhile, each demon was approached by the sun god and tasked with helping Michaela have Allen Avadonia meet one of their previous contractors, the Demon of Wrath's being Nemesis Sudou. After the demons agreed to cooperate, Seth was worn on the Master of the Hellish Yard's face while she began collecting other former contractors who escaped the underworld. He thus accompanied her while she collected all of them but the living Nemesis, to whom she sent Allen directly.
When Nemesis' soul was later reunited with her body, Seth joined Gumillia, Allen, Michaela, and Nemesis on the destroyed ground world. While Nemesis was talking to Gumillia, Seth took part in the conversation, asserting how he'd fulfilled his promise as Gumillia remarked more bitterly on the way he'd achieved it. Afterwards, Seth accompanied the group as they set out to save the world. Later on, Gumillia and Seth separated from the group, rounding up the other contractors and dragging them to hell.
When a fight broke out between the contractors that led all of them being blown out of the Hellish Yard, Seth laughed as Gumillia had to start over. During Allen and Nemesis' confrontation with Ma, Seth was asked by Nemesis to break his demon contract with her. As Ma fell to the ground, having swapped into Nemesis' body, Seth broke the contract, thus resulting in her death.
Sometime after, Seth encountered Banica Conchita and shared his research with her, asking her to be his guinea pig for Neo Black Box and met with her acceptance. He then handed it over to her, allowing her to travel to a parallel world. Seth was presumably incorporated into the new world created by Allen and Riliane's Re_birthday.
Seth's tampering with the creation of the Third Period led indirectly to the creation of forest spirits. It also led to the infection of several individuals with HER Syndrome, and made it possible for the Third Period's humans to develop the condition in the new world. Similarly, following his death as a human, the seeds of malice Seth implanted in his ghoul children were released into the atmosphere in the wake of their deaths during the Levianta Catastrophe, making it further possible for a HER to be naturally born in the Third Period.
Seth's surviving ghoul children continued to exist, the remaining five eventually being cryogenically frozen and kept in stasis at an underground facility deep below Castle Hedgehog and guarded for centuries. One ghoul child eventually reawakened and escaped, mixing with the ground world's humans to become the Freezis Family; the remaining ghoul children were later terminated a century later by their keepers on Behemo's orders.
Seth's creation of the "boy" of destruction during the Magic Kingdom Levianta contributed directly to the end of the Third Period, as did his time spent with Nemesis as the Demon of Wrath; as the Demon of Wrath he had indirectly influenced multiple souls throughout the centuries. Conversely, while accompanying the Master of the Hellish Yard Seth contributed to more direct management over the Third Period's afterlife, as Gumillia judged the dead for their sins and sorted them into Heaven and Hell.
Personality and Traits
- "But, you can't return to the ground world."
"I don't care. I was already bored with that place. And the people here in hell are likely to allow me to see numerous and new discoveries. I'll begin with my new research here from now on."
- ―Behemo and Seth[src]
Seth was a cruel, opportunistic, yet lackadaisical man. As an HER, Seth had no scruples against any evil action to accomplish his goals, which were to spread HER Syndrome and enact widespread destruction. As such, he particularly took pleasure in human experimentation and the study of Hereditary Evil Raiser Syndrome itself, hoping to develop more HERs in more efficient ways. Seth typically caused malice by manipulating people and events under the radar, influencing others to do evil rather than enacting widespread killing himself. As time passed, his ambitions appeared to wane until he was completely apathetic about the fate of the ground world.
Similarly, Seth took pleasure in the suffering of others, finding peoples' setbacks laughably hysterical. Although willing to cooperate with others, he typically only did so if he would be the one benefiting and could be extremely deceptive, as well as sometimes taking advantage of others' inexperience or ignorance to manipulate his deals unfavorably. His love of suffering was matched by his thirst for knowledge and discoveries, which at times overrode his leanings as an HER. He was therefore proud of his achievements as a scientist, while also incredibly ruthless in his research.
Skills and Abilities
- "If he weren't a HER, it wouldn't be odd for him to be the fifth god."
As a scientist, Seth was very intelligent and extremely knowledgeable in the technology of his fellow earthlings, making a name for himself as an inventor and physicist. Due to his years of research and study, he became an expert in the transference of spirit data and could move souls into inanimate objects and grant them an ageless immortality. His studies of Levia and Behemo's creation of the human mind and body likewise led to his development of both Black Box Type S and ghoul children, inventing multiple methods of creating the latter.
Despite this, Seth was limited by his true form as a mask with a will, helpless without any limbs. He was nonetheless significantly sturdy and, while being worn by someone, the mask was able to grant his wearer the ability to see in the dark and read minds. While incarnated as a human, Seth suffered blindness in his left eye and needed to wear glasses to supplement his poor eyesight. In Grim the End, Seth could also overcome his helplessness by utilizing the vessel's shape-shifting ability to become animals or a human.
As a Demon of Sin, the Demon of Wrath was able to possess those who wielded his vessel. While possessing a host, Seth was able to influence their personality and actions, fueling their anger and rage. If a contract was forged between an individual and the demon, Seth's host would have access to powers provided by him and be automatically healed when seriously injured, making the host essentially immortal unless counteracted with the power of another vessel of sin. He could also communicate with his host through telepathy, as well as read their thoughts.
Aside from this, Seth was capable of impersonating an individual, appearing before his host in the being's guise, and allow the host to release blasts of energy from the vessel. Although inhabiting the body of his host while possessing them, the Demon of Wrath's true body remained in Grim the End. Because of this, the Demon's powers could be inhibited by a sealing spell; similarly, the demon was forced to abide by the "rules" put in place by the sun god until the end of the Third Period. However, after being thrown out of his vessel and into the Hellish Yard, Seth was able to act more freely. He was able to share his power with another soul to act as his familiar.
Gumillia: A fellow former earthling. Seth admired Gumillia's capabilities in the Second Period and was impressed by her continued excellence after incarnating as a human; due to this, he was willing to bargain with her in order to make use of her capabilities when necessary. Despite any previous relationship he may have had with her, Seth was nonetheless willing to manipulate her with emotional blackmail, and the two had a vitriolic partnership.
Behemo Barisol: A colleague of Seth's in the Second Period. Seth copied his method of creating humans when creating the first Ghoul Child; because of this, the two had a vitriolic relationship.
Levia Barisol: A colleague of Seth's in the Second Period. Although in the Second Period they had a reasonable working relationship, Seth used Levia as a means to his ends in the Second and Third Periods, and later when he was charged with her safety as Nemesis.
Adam Moonlit: An associate of Seth's. Initially, Seth antagonized Adam in taking his mother away from him and had no particular interactions with him, but would later be able to tolerate sharing a vessel with the human for large amounts of time and allowing him to carry out contracts on his behalf. Despite this, while sharing Grim the End with him for centuries, Seth garnered no visible fondness for Adam.
Pale Noël: One of Seth's creations. Seth created Pale as a means of spreading HER Syndrome and had no scruple against unleashing him to cause havoc in Levianta. Although providing a cover story that they were twins to hide his human experimentation, Seth nonetheless regretted Pale's havoc becoming so easily associated with him due to their similar appearance.
Kiril Clockworker: One of Seth's creations. Seth created Kiril as a means of spreading HER Syndrome but appeared to have no visible affection for his creation. Due in part to wishing to keep his own human experimentation a secret, Seth hid their connection and deceived Kiril for his own ends later on, pretending to be a ghoul child himself.
Meta Salmhofer: One of Seth's creations. Creating her only for the purpose of spreading HER Syndrome, Seth showed no sense of responsibility towards her as a creator, abandoning her as a child, and later had no compunction against using her for his own ends during Project 'Ma'.
Irina Clockworker: One of Seth's creations. Creating her only for the purpose of spreading HER Syndrome and to be a sister to Kiril, Seth later had no scruple against using her for Project 'Ma' and saw use in prolonging her survival to continue spreading HER Syndrome in Evillious. He also saw fit to confide in her about the mechanics of the Third Period.
Nemesis Sudou: Seth's charge. Watching over her as part of a promise to Gumillia, Seth took every measure to keep Nemesis alive, even if it meant deceiving her, and watched over her in her formative years. As their relationship developed, Seth also encouraged Nemesis to take action and use Grim the End to lash out at others, pleased to help make her enemies suffer. He regarded Nemesis, while still alive, as Nemesis, in contrast to Michaela and Gumillia who identified her by Levia's previous incarnations.
Conceptualization and Origin
- Seth's name is likely a biblical reference to the third son of Adam and Eve, sired after the demise of Abel at the hands of his brother Cain.
- His last name, Twiright, likely shares the same wordplay with Twiright Prank, acting as a pun on the word "twilight" and creating a portmanteau of the words "twist" and "right".
- Seth's description as a "serpent" acting behind the scenes in the Original Sin Story: Complete Edition album likely references the biblical serpent of the Garden of Eden.
- The demon's representative sin is derived from Wrath of the Seven Deadly Sins; Satan, the patron demon of Wrath, is commonly interpreted as being the serpent of the Garden of Eden in Christianity.
- Seth manifests himself in the form of a mask; in literature, masks often symbolize concealing one's identity.
- In the Escape of Salmhofer the Witch song PV, the R in Seth's surname is capitalized in a similar fashion to the L in Eve Moonlit's surname.
- Humorously, the Original Sin Story: Complete Edition booklet states the serpent always wears a mask when describing Seth's numerous identities.
- According to mothy in a Q&A, he at one point envisioned Seth as being the final villain, although discarded the idea while writing him; he additionally explained that Seth might be a more standard villain in a hypothetical novel for the Original Sin Story.
- During the same Q&A, mothy stated that destroying Seth's mask form could kill him, although it couldn't be destroyed through normal means similar to the vessels of sin.