Noumi Seiji (能美 征二, Noumi Seiji?) is a 1st year student at Umesato Junior High School and is a member of the Kendo club. He is the main antagonist of the third and fourth arc of Accel World.
Seiji is an extremely twisted person, whose personality stemmed from the years of extreme bullying he received from his brother since his childhood. He is a hardcore Burst Linker due to constant misusing acceleration to gain perfect academic scores and excelling in Kendo matches and is shown to be utterly merciless as he even blackmails in the real world to make other players give him points and work as slaves for him. He has a very strong disdain for bonds and friendship, due to his past where his only friend betrayed him under his older brother's influence. Thus Seiji has immense hatred for his older brother. After losing Brain Burst, he has become very kind, pleasant and carefree. Due to the loss of Brain Burst erasing his memories as a Burst Linker as well as the memories of all the immense emotional pain and abuse he has suffered at the hands of his brother.
Seiji Noumi had an extremely unhappy childhood as his violent and extremely selfish brother, Noumi Yuichi would forcefully take toys and money from Seiji, even forcing his only friend to sever their friendship and betrayed him, at some point Seiji was introduced to Brain Burst by his brother, Yuichi threateningly forced him to fight numerous Duels to earn Burst Points and give Burst Points to him regularly, even to the point of slavery. This proves to be a breaking point for Seiji's sanity, his anger and hatred reaching its absolute peak. As Seiji gained more combat experience as a Burst Linker, he slowly accumulated sufficient burst points to level up and strengthen his Duel Avatar gaining his Demonic Commander ability. As his battle experience in the Accelerated World continued to increase, he eventually learned of the incarnate system. He then tricked his older brother into the Unlimited Field, subsequently stealing his brother's Duel Avatar's ability rendering Yuichi utterly defenseless against Seiji's vengeful rage. Seiji then used Incarnation to brutally torture his brother to death; a process that Seiji repeated until Yuichi lost all his points. He later joined the Acceleration Research Group.
Seiji has a medium stature, dark brown hair which he has in a bowl haircut and brownish gray eyes. As for his attire, he has been seen in Umesato's school uniform which consists of a white dress shirt with a light blue blazer on top and a green tie.
Dusk Robber Arc
- Main article: Dusk Robber Arc
Seiji arrived as the first year at Umesato Junior High School. He was later revealed as a Burst Linker when he soundly bested Mayuzumi Takumu in a kendo match. Takumu theorized that Seiji used Physical Burst, which allows a Burst Linker to accelerate for three seconds at the cost of five Burst Points.
Takumu tried to confirm whether Seiji was a burst linker by trying to connect to his Neuro Linker but failed to do so, he sent Haruyuki a picture of a graduate of Umesato Junior High School from 3 years ago who he believed to be Seiji Noumi's Elder Brother, unknown to Takumu and Haruyuki at the time, the picture contained a visual masking virus that was installed into Haruyuki's Neuro Linker. Haruyuki began to tail Seiji the next day but the latter was on to him and lured him into the girls' shower room due to the visual masking virus in Haruyuki's Neuro Linker mixing up the gender signs on the wall. The next day, he arranged a meeting with Haruyuki, revealing that he had secretly placed cameras recording Haruyuki entering the girls' shower. He then began to blackmail Haruyuki, demanding that he give Burst Points every day if he doesn't want to be expelled. Chiyuri Kurashima then arrived, trying to cover for Haruyuki, only for Seiji to reveal one of the cameras to the school. He then grabbed Chiyuri, telling her to cooperate and root for him as he attempted a direct link with her. Afterwards, Haruyuki charged at him and they both used Physical Burst. But but due to Haruyuki's inexperience with the command, he was beaten. Seiji then pinned the boy to the ground with his foot and direct linked with him as he challenged him to a match. In the duel, Dusk Taker defeats him after using his special ability, "Demonic Commandeer" to steal Silver Crow's ability to fly and rendering him powerless. After stealing Silver Crow's flying ability, Seiji promised to return Silver Crow's wings when he graduates, on the condition that he gives Burst Points to him every day. The next day, as Seiji was taking a test, he was challenged to a match by Takumu, who knew he would accelerate during the test and that he stole Silver Crow's wings. Even making him at disadvantage with his stolen abilities in the match until then.
In the duel, Seiji demonstrated the power of the Incarnation System, enabling him outdo Cyan Pile. And after Cyan Pile is close to be defeated, Silver Crow's manages to beg Dusk Taker to take his point instead of Cyan Pile's, which make Dusk Taker into switching to Battle Royale mode so he can fight against him too. In instance, Silver Crow activate his incarnate attack and manage to cut off one of his arms. As Dusk Taker recovering from the attack, he activates flight ability and fly upward to get out of Silver Crow's effective range. Next, he equip Pyro Dealer, a long-range fire element Enhanced Armament. After avoiding the fire that breathed out by the Pyro Dealer, Silver Crow equips the Gale Thruster he received from Sky Raker, to attack Dusk Taker head-on and manages to deal a large amount of HP (Health Point) to him with assistance from Takumu. However, before Haru can finish him, Lime Bell appears and use Cintron Call on Dusk Taker.
Afterwards, Seiji flaunts his ownership over Haru's wings and Lime Bell's healing ability. This causes Haru to attack Seiji, but he is pushed back as Taku advances forward. Seiji quickly uses the Incarnate system to tear Taku to shreds, causing Chiyu to scream and Haru to become even angrier. In his anger, the Chrome Disaster armor that attached on Haru begins to entice Haru into brutally destroying Seiji. Haru eventually succumbs to the temptation and uses a darker version of his incarnate system to attack Seiji, screaming at Seiji to get out of his life and disappear. Eventually, Seiji has to use both hands powered by his incarnate system to hold Haru off, but just as Haru was getting the upperhand, the match timed out, causing all the players to go back to the real world.
Flight Towards the Blue Sky Arc
- Main article: Flight Towards the Blue Sky Arc
Seiji soon leaked a rumor that Haru planted the camera in the girls' shower room, which led to him being questioned by a staff member and unjustly beaten up by a fellow student whose girlfriend was embarrassed by the revelation. Seiji stared at Haru in triumph as his rival ate his lunch without crying.
Over the next little while, Seiji, with Chiyu by his side, began to dominate the Suginami area, devastating entire opponents in the normal matches. It was his ambition to eventually become powerful enough to challenge Black Lotus and rule Suginami.
A few days later, Haru confronts Seiji in the same bush where he first challenged him. He reveals that he knows he's using an illegal brain implant chip to hide from the matching list and to cheat on school exams, only activating his Neuro Linker to challenge people, to Seiji's surprise. One scan and Seiji would be expelled, his implant chip forever deactivated.
Seeing that he knows his secret, Seiji offers a chance to end their feud once and for all by wagering all their Burst Points in the Unlimited Field in a Sudden Death Match.
However, Seiji was not seeking to fight fair. He enlisted the assistance of Black Vise, vice president of the Acceleration Research Society, to trap Haru while he engaged Taku. However, Taku revealed to mastered the incarnate system, turning his pile driver into a sword. They then dueled, eventually slashing off Seiji's left arm. Taku then observed that from his duel avatar's name, he can never truly own the things he steals, which is why he's left with nothing. Seiji simply laughed, revealing how came to possess Brain Burst and avenged himself upon his bullying older brother. He then manifested a new arm, which he used to constrict Chiyu and torture her, causing Taku to lose his will to fight. Seiji then proceeded to viciously attack Taku. His sadistic attack soon gave Haru the strength to break free of Vice's grip. But before Seiji could land the killing blow to Taku, his right arm is severed by Black Lotus, whose duel avatar had journeyed all the way from Okinawa. She held off Black Vise while Haru faced Dusk Taker for what may be the last time.
Seiji merely laughed at Haru and the thought that their bond of friendship could defeat him, promising to take his time with him just like he did his brother. Haru told him that his biggest mistake was not challenging normally him when they first met. If he had, Seiji would've gained what he wanted most: friendship. However, he is not seeking to befriend him, seeing that Seiji is beyond redemption. Silver Crow and Dusk Taker then engaged in an aerial battle. When it seemed like Haru was going to win, Chiyu suddenly used her healing ability on Seiji. The tide had turned and Seiji had Haru in his grasp. Then suddenly, his wings disappeared and were returned to Haru. As Seiji went into freefall, Haru used the combination of his wings, Laser Sword and Gale Thruster to deliver a crushing blow to his opponent. By then, all what remained of Dusk Taker was his upper torso, head and left tentacles. Chiyu reveals to Seiji that she's come to the revelation that her healing ability, in fact, reversing time on duel avatars, given that his equipment regenerated the first time she healed him. Thus, she pretended to join him long enough to level up her killer move to the point where it could reverse time to before Haru lost his wings.
Cursing the Nega Nebulous, Seiji vowed to leak their real identities and called on Black Vise to help him. Unfortunately, Black Vise was tied up holding off Black Lotus. Seiji demanded that he do something, threatening to expose the Research Group and the BIC. Black Vise reveals that the BIC will dissolve into the cerebrospinal fluid once it senses Brain Burst's uninstalling. He then vanished into the shadows.
Left with no allies, Seiji started pleading for his life. He attempted to bargain points and his service in their legion if they spare him, but his pleas fell on deaf ears. Growing frantic, Seiji tried crawling away, only to be sliced in half by Haru. Dusk Taker was then destroyed, once and for all.
The next day, Haru met Seiji at school, now a much more pleasant person without Brain Burst, though he could not recall the game.
Dusk Taker has a tall black and purple body with a red orb as his face. There are two similar orbs on each of his shoulders. His left hand is normally equipped with an Enhanced Armament that takes the form of triage of tentacles with the power to regenerate, which he apparently stole from another burst linker called "Starfish". His other hand is equipped with another Enhanced Armament that looks like a giant metal claw that has extremely strong cutting power, and which he sometimes exchanges with for a large red flamethrower-esque cannon known as Pyro Dealer which is capable of firing great blasts of flames like a dragon, that can burn the stage's ground into lava. However, it was not stated who he stole either of these weapons from. Dusk Taker also has gained a pair of wings that look like torn bat or demons wings that he stole from Haruyuki's Duel Avatar, Silver Crow.
Dusk Taker is unique duel avatar due to its ability to steal the ability of other Burst Linkers, and due to his past where he was forced to regularly to give Burst Points to his older brother, Taker spent an enormous of battle time in the Accelerated World, thus he has immense combat experience as a Burst Linker when compared to other Burst Linker beginners such as Cyan Pile and Silver Crow, despite his level being lower than the other Six Kings and their close aides, he has superior tactical prowess and versatile mastery of the Incarnate System. This makes him a exceedingly strong Burst Linker when combined with his arsenal of Enhanced Armaments and special abilities which he stole from other.
- Demonic Commandeer: Dusk Taker main ability which was born from Seiji's extremely painful trauma of his dark past where he suffered extremely cruel emotional abuse by his older brother, it allows him to steal one of three things. Which is: 1. an opponent's special move, 2. their enhanced armaments, or 3. their abilities. Once Dusk Taker has taken one of these 3 things, he can use them however he wants. He can swap out whatever he steals at any time and keep them for as long as he so chooses. He can also give anything he steals back to the Burst Linker he stole it from, but usually he doesn't give them back given his twisted nature. According to Dusk Taker himself, there is a limit on how many he can hold such as abilities, armaments and such that he can steal, but the exact number is not revealed. However, this ability is not foolproof. Dusk Taker is unable to steal abilities or armaments from opponents which have been crafted from very dark or vicious traumas or memories, as shown when he is unsuccessful in stealing Cyan Pile's Cyan Blade and explaining why he did not attempt to steal Lime Bell's healing ability, as both are deeply forged from their owners various traumas.
- Dusk Claw: Taker's incarnation skill which envelops his hands in a dark purple energy that allows him to slash through even hard materials that normally can't be break without sufficient firepower, except for other incarnation skills that strong enough to counter his claws. When using incarnation Taker can also shape his claws to take on the shape of his octopus arms and Silver Crows's Sword Laser. His incarnation skills do not shine like Silver Crows' and Scarlet Rains as the emotion which empowers his incarnation was born from his past despair rather than hope. His Incarnation claws are also powerful enough to defend against Cyan Pile's Level 4 Special move Lightning Cyan Spike as well as Silver Crow's Disaster empowered Laser Sword his claws also grant him great physical strength enough to throw around the bulky and heavily armored Cyan Pile as well as brutally overpowered his older brother's massively large Duel Avatar.
- Incarnation Blade : Taker can use Incarnation create a makeshift energy blade that is strong enough to clash with Cyan Pile's Cyan Blade.
- Pyro Dealer: An Enhanced Armament that Taker likely stolen from another burst linker; when equiped his arm turns into a red and black cannon that fires magma-like fire.
- Speed: As Cyan Pile stated, Taker's is a speed type Duel Avatar, which makes Taker a very fast opponent in combat, even before acquiring Silver Crow's wings, Taker was fast enough to match Silver Crow's extraordinary speed and reflexes. When used in with his Incarnation Claws, makes him a very dangerous fighter as he quickly block Cyan Pile's special move and counterattack just as quickly.
- Starfish Tentacle Arms: An Enhanced Armament stolen from another Burst Linker, Taker's left arm turns into three tentacles that he can use to bind his opponent and can regrow them if they are cut off.
- Flying Ability: After using Demonic Commander to take Silver Crow's wings Taker grows wings of his own but are more sinister looking due to the different Avatar Colour Taker has. Silver Crow recovered his wings later due to Lime Bell's Citron Call ability.
- Taker stole two other Linker's abilities who probably were bullied by someone like he was.