|Alias||Knight King (騎士王, Kishiō)|
Idiot (バカ, Baka)
|Relative(s)||Mr. Boyle (Father)|
Mrs. Boyle (Mother)
|Voice Actor(s)||Yūsuke Kobayashi (voice actor) (Japanese)|
Yuka Terasaki (child)
Eric Vale (English)
|Birth Date||July 10th (Cancer)|
|Height||174 cm (5' 8½")|
|Weight||64 kg (141 lbs)|
|Affiliation||Special Fire Force Company 8|
|Rank||Fire Soldier (Second Class)|
|Manga||The Devil, The Knight, and The Witch|
|Anime||The Heart of a Fire Soldier|
Arthur is a young man of average height and lean but muscular build with shaggy blonde hair and blue eyes with white pupils, similar to Shinra. He tends to style his hair upwards into a ponytail when in a fight, so that his field of vision would be clearer. When Arthur was first introduced, he wore a dark jacket, with a button on his collar, shaped like a cross-like insignia, light shirt, dark pants, a belt and dark shoes. He was later presented with a bunker gear, a protective outer jacket and trousers. Arthur carries a scabbard alongside him, in which he keeps his blade-less sword. Parts of his outfit, are coated with blue lines. Arthur wore a dark green jumper with a hoodie, which he put on his head instead of a helmet. The buttons of his protective jacket are in the shape of cross-like symbols. Arthur's outfits contain patches with "8" on them, to signify his affiliation to the 8th Special Fire Brigade. He also dons a neck protector and protective gloves. When attiring the 8th bunker gear, Arthur chooses not to wear the helmet, as it doesn't fit his image of a knight.
Currently, after battling with Dragon Arthur lost his left forearm as well as gained a large scar across his right eye. After his final strike against Dragon, Arthur lost his entire lower half of his body. He later seemed to have regenerated his lower half.
Arthur is confident in himself as a Third Generation pyrokinetic, so much that he appears arrogant and cocky all the time, notably for his habit of refusing to use honorific speech regardless of who he is talking to. Arthur has a habit of repeatedly saying "Hmph" in response to people, coming across as stubborn or dismissive. Due to his attitude and casual demeanor, Arthur tends to make bad impressions on people. But like the other fire soldiers, He was shown not to be bothered by human antics  and Arthur is usually nonchalant even while struggling in fights. According to Shinra Kusakabe, he is popular with the girls and seems to always have a silent and mysterious façade, though Shinra thinks he's just too stupid to articulate anything. Arthur often bickers with Shinra about almost anything, starting with which are superior: knights or heroes. In spite of this and constantly calling Shinra a 'Devil', Arthur is able to effectively work with Shinra as a team. He also has faith in Shinra's heroism and strength, even helping him regain them at times, but chooses to express it very rarely. Arthur often disregards orders and common sense to do things his own way, such as charging in ahead extinguishing Infernals while leaving his support team behind.
He has a fantasist-like complex, potentially as a way of coping with parents abandoning him and the dangers of the world. These fantasies cause him to act like a mediaeval knight, and to the ordinary person, he may appear idiotic or deluded. Arthur's strong sense of justice is correlated to his knightly persona but is a welcome trait among Fire Soldiers. This involves Arthur referring to the girls he meets as princesses and the Special Fire Cathedral 8 as his castle. Arthur sees the world in a different light; he believes the pigeons to be griffons and that he was successful in slaying dragons. Arthur takes great pride in Excalibur, and in his personal tool's absence, his power is directly linked to how "knightly" he feels, which includes how sword-like any acquired tool look. Damaging or losing it causes him to lose most of his confidence and leaves him disillusioned until it can be repaired. As a Knight, Arthur possess an incredible determination. Something showcased time and time again as refuses to surrender in any serious bout, fighting until he is unable to stand even if it kills him. Because of this strength and seeing wonder in a cruel world Arthur is able to find hope or enjoyment in the most dire situations.
Other than his eccentric demeanor and obsession with the medieval, Arthur is also known for his lack of intelligence, repeatedly been referred to as an idiot. This mockery turns out to be true, as he is utterly incapable of anything of requires heavy thinking, quickly burning out from paperwork and he is unable to generate or comprehend complex strategies. As a result Arthur relies on his natural combat instincts to fight. However his instincts have sometimes proven to be more valuable than intelligence, such as recognizing when one of the twins was fake when no one else could, and defeating a member of the white clad using his instincts and training he received from Benimaru. Above all else, Arthur's delusions of wonderful fantasy and simplemindedness mean that he enjoys his life to the absolute fullest and cannot despair about his situation.
According to Haumea, Arthur is the Fourth Pillar's Guardian. This is proven when he snapped Shinra out of despair, as well as giving him hope and not giving up, as Shinra is the only one who shouldn't give up. Even reminding him who he is, and that he is a hero.
Arthur was an only child whose parents owned a small restaurant. They earned a meager living until their financial situation worsened; not only did a guest get food poisoning but the restaurant was subsequently burnt down.
One night, after seeing an unfavorable report about their business on the news, his mother tells Arthur to fetch his father for dinner. His father is in the adjacent room, napping with his hat over his face. After waking him, he asks his dad what inside the hat had him so interested in. His father playfully tells him to look into the hat allowing Arthur's imagination to take over. He reinvents his surroundings as a beautiful castle of which his parents are the king and queen.
The next morning, he finds a letter from his mom and dad explaining that they left on an adventure to save the world, and that while they are gone, he is king. Arthur, seemingly abandoned, enrolled into the Special Fire Force Training Academy alongside Ogun and Shinra. At some point he would go to a hardware store to get enough fire-resistant carbon to make the hilt of his Excalibur.
Arthur has proven himself to be one of the strongest Fire Soldiers in the Special Fire Force. Arthur is an exceptionally strong Fire Soldier, possessing incredible physical strength that allows him to repel an Infernal with a single punch. With time he becomes one of the strongest people on the planet. Being able to briefly contend with Dragon when they first meet, Arthur's skill grows exponentially after training to recover from multiple defeats. Arthur's speed allows him to react quickly enough to retaliate against Shinra’s Rapid and he was fast enough to react to Shō Kusakabe's Severed Universe, though he wasn't able to entirely dodge it. Arthur also possesses tremendous durability, being able to withstand damage and powerful blows without staggering or relenting in his own attacks.
He is eventually recognized by Dragon to be the first person to draw blood from him in a fight, and has managed to critically injure the latter on multiple occasions during their brawl. He managed to match his immense physical abilities as well as using his incredible speed to catch him off guard or avoid lethal attacks.
His final, strongest attack, Violet Flash: Earth Divider, was so incredibly powerful, it completely split the world in two, along with instantly killing Dragon. The light from the attack also managed to extinguish some of the flames of the Great Cataclysm. This attack, along with the rest of his abilities, proved that he is one of, if not the strongest beings in the series so far.
Immense Strength: Arthur possesses superhuman levels of strength, showcased in his battle against dragon, when he was capable of trading blows with the Monster with relative ease. His immense strength was enough to break apart the surface of the moon and Dragon’s impenetrable armor, which survived countless plasma strikes. His strength allowed him to slice through Dragon’s impenetrable armor with no difficulty. His strength allowed him to contend with several Infernals in terms of strength as well as create shockwaves upon clashing with Dragon several times in their final battle.
Immense Speed: Even more so than his strength, Arthur possesses unimaginable levels of speed. When embracing his knightly delusions, his speed matched that of Shinra’s Rapid, and allowed him to contend with and catch Dragon off guard in their final apocalyptic showdown, and even use his Plasmantle to move faster than the speed of Lightning. When using the Star ring, his speed drastically increases, to the point that he can move fast enough to easily traverse the vacuum of space and cross the distance from the Sun and Earth with barely any difficulty, and completely overwhelm the likes of Dragon with unrelenting attacks.
Immense Durability: Arthur possesses incredible durability, shown as he was able to ednure blows from demon infernals and Benimaru Shinmon. His durability shines through in his rematch with Dragon, where he managed to survive hundreds of immensely powerful attacks from the Beast. His durability allowed him to survive Dragon’s final attack, losing his lower half in the process. Even after all of this, he still managed to hold on for several minutes in space, but later succumbed to his grievous injuries. Arthur also has a large amount of oxygen in his body and a high resistance to fire, showcased when he survived several of Dragon’s explosive fire attacks and fought against him for several hours without overheating whatsoever (this could be explained as him using the Star ring however).
Immense Stamina: Arthur possesses an incredible amount of energy and stamina, allowing him to fight for several hours without Overheating in his training with Benimaru Shinmon, and fight for an extended period of time against Dragon without wavering. He also managed to fight for several seconds in the vacuum of space without falling unconscious until finally succumbing to its effects. Upon donning the Star Ring he managed to completely ignore most of Dragons attacks, fight for several hours without tiring, and more. He also possesses a surprisingly high pain tolerance, allowing him to fight despite being grievously injured by Dragon and smile despite missing several body parts.
Indomitable Will: Arthur’s most well known feat is his inability to give up. He has showcased this aspect in every single fight he’s participated in, fighting on and on until he is no longer able to stand. Arthur fought dragon for an entire day despite being outmatched by him at first, and even managed to fight him for multiple hours in outer space. Before equipping the Star ring, Arthur still managed to survive in space for a few minutes before succumbing to its effects. Even after experiencing severe blood loss, and losing body parts, Arthur managed to use Steeled for Death in his final attack to finally vanquish Dragon. Even after being cut in half and heroically sacrificing himself to protect humanity, the Knight King still called out to Shinra as a last resort, telling the Hero that he has finally conquered the dragon and has become the Knight King, and leaving the rest to the hero, finally accepting that knights defend the world, while the heroes save it, before finally dying in peace.
Being a Third Generation, Arthur has been identified by individuals as having a strong will of fire. Arthur attended the Special Fire Force Training Academy alongside Shinra and Ogun, where he was hailed amongst the populace for having the strongest raw firepower among the students.
By raising the temperature of the flames he creates, he can conjure and control plasma, a rarity as few can heat flames into a plasma state. In addition to his natural resistance to fire, Arthur also has a large amount of oxygen in his body. This allowed him to fight against Benimaru for several hours before he collapsed from overheating. The effectiveness of his ability either elevates or diminishes in relation to Arthur's disarrangement from reality. The more delusional he is, perceiving himself as a medieval fantasy-world knight, the stronger Arthur becomes, whereas being pulled back to reality reduces his strength. His ability as a plasma user also makes him immune to electric shock pyrokinetic abilities, such as Haumea's, as well as sabotages the electric shock ability.
Being able to use his Ignition Ability on hilt-like objects, Arthur can form a blade of plasma that he can use to weld, cut through metal, and generate electricity. He mainly uses his ability in conjunction with his bladeless sword Excalibur, which is most effective in his right hand and cannot be easily extinguished by an experienced Second Generation, although he could still use it effectively to a certain extent with his left. Using the blade, he can deflect and fend off flames as well as slice through different kinds of matter. The downside of his ability, linked directly to his warped worldview, is that he is incapable of using his abilities correctly unless the tool he wields resemble the hilt of a sword.
After training alongside Shinra Kusakabe with Benimaru Shinmon, Arthur learned to use Hysterical Strength. This required understanding the Press of Death, acknowledging the possibility he could die and allowing himself to push his body beyond his normal limits to ensure his survival, which resulted in his flames turning blue and which gave him a massive boost in power. For Arthur this power became his Plasmantel cape, a cape made of plasma that hangs from his shoulders. This cape has immense defensive capabilities against other flame attacks, even incredibly powerful attacks, like Dragon's explosive fire breath.
Arthur possesses incredibly keen eyesight, allowing him to track the smallest movements and react quickly, he can even follow Shinra while his speed is enhanced by Rapid. However, this instinct to react results in Arthur instinctively blocking and parrying any attack he sees, leaving him vulnerable to illusions and misdirection, though after his training with Captain Shinmon of Company 7, he learned techniques that allow him to distinguish illusion from reality and has overcome this weakness to an extant.
Like all Third Generation Pyrokinetics his strength was increased as the Stone Pillars emerged and Adolla encroached on reality. During the Cataclysm, Arthur was able to create a much stronger connection to Adolla than ever before and allows his reality to be shaped by his knowledge and perceptions of reality. By completely embracing his knightly delusions, Arthur was able to take inspiration from video games to drastically increasing his firepower. Even allowing him to cast spells he thinks are worthy of a knight and survive in space briefly, as he was unaware of the lethal effects of breathing in a vacuum. This imagination and faith allow Arthur to turn the Star Ring into a powerful object. Not only allowing himself to breath in space but letting Arthur tune himself to the thoughts of humanity to increase his powers even further. This allowed him to create an even more powerful version of Plasmantle to match Dragon's ultimate form.
Press of Death/Steeled for Death
After training with Benimaru Shinmon, Arthur managed to learn the Press of Death, a technique that allows him to acknowledge the feeling of death to push his body beyond his limits, achieving a state of Hysterical Strength. After fighting with Dragon, Arthur uses his greatest technique yet, Steeled for Death. As stated by Arthur, the Press of Death is only the acknowledgment of Death, which allows him to push his body to its limits. Steeled for Death is the extreme feeling that surpasses the Press of Death, that allows him to unleash his strongest attack while accepting the fact that he’s going to die. This technique allows its user to commit unimaginable feats of strength, in which standard attacks will become insanely powerful. This was showcased in the Final Showdown by Arthur, when a single Violet Flash completely split the Earth in two, and singlehandedly sliced Dragon in half.
Arthur arrives at the Special Fire Cathedral 8, where he runs into Shinra Kusakabe and the two begin fighting. As their fight is taken to roof, he meets Iris and Maki Oze, followed by Takehisa Hinawa, who instructs him to spar with Maki in order to test his abilities. Unable to beat her combat skills and ability, Arthur gives up. After eating at Ippudo Ramen, Arthur is offered a battleaxe, but refuses to take it. When the brigade is notified of an Infernal in the Iriya District, he departs to the scene. While on route, Akitaru Ōbi instructs Arthur and Shinra to conceal their weapons in public, much to his confusion. After their arrival, Akitaru pulls the two aside for disobeying orders, where Arthur questions the instruction, leading Akitaru to justify his reasoning. After their conversation, a burst of flames emerges from the apartment, prompting the brigade to storm the building and find the Infernal. Arthur volunteers to put the man out of his misery and impales his core. Immediately after that, the ceiling begins to collapse, but the brigade escapes unscathed.
Arthur participates in the Rookie Fire Soldier Games. When the simulation exam starts, he charges towards the building and uses his sword to slice his way in. After one of the entrants bombards the building with his ability, Tamaki Kotatsu falls onto him, which gets the two into an intimate situation. Following his beliefs, the boy allows Tamaki to take the lead when exploring their current location. When the two are attacked, Arthur jumps in to defend the girl. He then charges in, believing Joker to be part of the exam, despite Shinra's warnings, but does not land a single blow. When the man uses an unknown substance to put their lives in jeopardy, Arthur uses his sword to cut a hole in the ceiling, allowing Shinra to evacuate them all to safety, with Arthur being caught by his team-mates in a blanket.
The following day, Arthur accompanies Shinra on his mission to rescue a dog, who was reported to be stuck in a tree, and afterwards, helps Mamoru hand out balloons to children. The two then learn of an accident in the courthouse from Takehisa, who was moving to the scene with the rest of the brigade. Grabbing a lift from Shinra, the two Fire Soldiers face Setsuo Miyamoto, with Arthur hitting the opponent with a backwards fist and delivering a collaborative attack alongside Shinra. When the brigade catches up to Shinra, Arthur and the rest find themselves in a confrontation with the Special Fire Force Company 5. Tōru Kishiri mocks Akitaru, which leads to Shinra and Arthur jumping in, but Maki and Takehisa detain the two. A stand-off between the brigades is then catalyzed, but the two depart without any signs of struggle.
VS. 5th Special Fire Brigade arc
The following day, Takehisa begins training the Fire Soldiers, having Arthur spar against Maki. Later, after Iris has gone missing, the 8th Special Fire Brigade infiltrates the Special Fire Force Combine 5, where Arthur finds himself in a fight against Setsuo, who was modified by the 5th Special Fire Brigade. Mid-way into the fight, Arthur realizes the whole time he had been fighting with Excalibur in the wrong hand, which is why he had been struggling so much. Before Setsuo could execute his final attack, Arthur finishes him off in a dash with Violet Flash, successfully exterminating him. After the two brigades ordeal ended, a dinner party was organized between them as a sign of reconciliation. As Maki created some of her Sputter and Flare, Arthur sliced all of them in half, stating that Takehisa told him to destroy them whenever she creates them.
VS. 1st Special Fire Brigade arc
Later at the brigades church, Akitaru instructs Arthur and Shinra to infiltrate the Special Fire Force Company 1 and uncover any secrets they may be hiding. A while later, the two and Maki arrive at the 1st Special Fire Fighting Cathedral, along with Tōru Kishiri and Takeru Noto. As they walk inside, they meet Karim Flam, followed by the other Company Lieutenants and Captain of the 1st. When Burns agrees for the newcomers to test their abilities, they go out to the courtyard and begin sparring. After Rekka and Takeru's fight, Arthur and Shinra confront Burns. Confident that he will defeat Burns, he charges at him heroically, but to no avail, as Excalibur is blocked and repelled, much to Arthur's confusion. Afterwards, Shinra tries his luck against Burns but is also defeated with ease, and the newcomers are welcomed to training with the 1st for the month.
On the fifth day of training, the brigade is notified of the appearance of Infernals, and departs with Shinra alongside Karim and Company 1 to the scene. When they arrive, Karim instructs the two to stay put, which they do, until Shinra notices a priest creating an artificial Infernal and takes chase after the culprit. As they stumble across Karim and Rekka, Arthur spontaneously confronts them about it, but is quickly subdued by Shinra. After the mission ends and they arrive back at the Cathedral, Arthur, still annoyed at Shinra for stopping him, questions why he did so. Shinra explains that by confronting them in the alley would have led to their defeat, as they were outnumbered by the amount of 1st Brigade members. The two then resolve a plan to infiltrate and investigate Rekka and Karim's room, starting with Karim. As they arrive, they discover the same Bug used to create the artificial Infernal, but at the same time are discovered by Karim. As Karim points out he is on their side, hiding the Bug on purpose to lead them there, he reveals that the real criminal is Rekka. A little while later, Arthur and Shinra await Karim in the corridors, and ask for permission to help with the capturing of Rekka, to which Karim tells them to do what they like. While hunting for Hoshimiya, Arthur gets lost in the city. The Fire Force has to file a missing person's report once the case is resolved.
Preacher Pursuit arc
Arthur finds his way back to Company 8 before the meeting of Fire Force captains. Upon arriving back at his brigades church, Akitaru has the Soldiers look through their mission records to find any leads on the Preacher and White Hoods. Arthur is told the story of Company 8's founding After Shinra reveals his brother is affiliated with the Preacher, Arthur questions the reliability Joker's information that he gave to Shinra.
Following a lead on the Evangelist, Company 8 travel to Asakusa. Meeting up with the Special Fire Force Company 7, their meeting is cut short when an Infernal appears within the district. As Benimaru Shinmon deals with the matter, Arthur questions how the brigade commander is manipulating flames, which Konro informs him that Benimaru has both Second and Third Generation powers. In the aftermath of the event, Arthur assists in the reconstruction of the destroyed houses, welding materials together with his Mini Excaliburs. When Benimaru begins to rampage through the town, hunting down Company 8, Arthur and Hinawa work together to challenge him but are quickly overpowered. Once the battle between Akitaru and Benimaru ends, Arthur walks through Asakusa with Konro and members of Company 8. The Knight King is the first to realise that Hikage is an importer, attacking the spy and revealing their true identity. Asakusa irrupts in flames. Akitaru instructs his team to assist the villagers evacuating, but they are immediately attacked by a flaming arrow. Shinra and Arthur then begin searching for the shooter.
When Shinra is attacked by a pair of White Hoods, Arthur defends him from Arrow's attacks and the two groups begin to fight. Realising they need to start coordinating their attacks with one another and adjusting their strategies, the Fire Soldiers manage to get the upper hand. When Arthur corners Arrow, Haran intervenes and gets slashed by Excalibur. Wounded, Haran swallows a Bug and transforms into an Infernal. With his new found strength, Haran overpowers Arthur and the Soldiers are engulfed by his fire ball. Jumping back into the fight, Arthur attempts to cut his horns, but is unsuccessful, before being repelled again. Haran's assult is interrupted by the arrival of Benimaru. Arthur advises Benimaru that his martial arts will not harm the Demon, inspiring the Composite fire soldier to launch Haran into the air. He later witnesses Shinra's deflection of Arrow's attack and Benimaru vanquishing Haran for good. Company 8 return to their headquarters after the reconstruction of Asakusa is completed.
Vulcan's Workshop arc
After the brigade returns to their church, Akitaru tasks Arthur, Shinra and Iris with going to Vulcan's workshop to make a good impression on Vulcan. Upon arrival, Arthur announces his presences, which leads to him being attacked by flames and cans. The group is then met by Yū, who manages to get them into the workshop. Afterwards, everyone in the workshop goes outside, where they witness a projection that Vulcan made.
Shortly after, the White-Clad arrive at the workshop, leading to Vulcan making Arthur a knight's arsenal in order to fight the group. Outside, he meets Flail, and attacks the group with his make-shift Excalibur, resulting in all but two of the white hoods dissolving. After, he fights Flail and slices through his Ignition Ability. When Mirage makes a mirage of Arthur, he becomes sadden by his attire, followed by Flail attacking him. Standing back up, Arthur wows to not forgive Flail for destroying his steed despite his powers weakening significantly. Arthur is eventually overwhelmed by Mirage's tricks and fails to stop Giovanni from entering the workshop. Flail stands between Arthur and the Workshop to prevent him from chasing the turncoat captain. When Shinra manages to outmaneuver their opposition, Arthur mocks the Ash Knights for failing to stop him. Their battle is interrupted by Princess Hibana dispelling Mirage's illusion and bombarding everyone with waves of intense heat. Much to Arthur's disbelief. Arthur and Flair are eventually saved by Iris activating all of the robotic animals in the area.
After Shinra knocks Giovanni through a wall, he and Arthur regroup and encounter the long-missing Shō Kusakabe. While Shinra is overjoyed, Shō remains indifference, and callously brings Shinra to his knees. Arthur readies an attack but Shō defeats him with a slash to the chest. Arthur, Shinra, and Hibana are rescued from danger by Viktor and Vulcan. The surprise intervention of Joker ensures the group escapes and arrive safely at hospital, Arthur quickly recovers from his injuries and life returns to normal for Company 8.
Arthur and Shinra are sent to train with Company 7 in order to ready themselves for future battles with the White Hoods. During this training, Arthur learns traditional Japanese sword fighting and how to focus his senses in battle to detent killing blows.
Arthur and the rest of Company 8 enter the Nether to confront the White Hoods. Arthur expresses fewer worries about entering the forbidden underground Labyrinth than his allies. The Company they are confronted by Princess Hibana, begging for help before being pulled screaming into the darkness. Before the group can proceed, mist envelopes them and they are separated in the confusion.
After his battle with Arrow and before Yona and Mirage can kill him, Hinawa forces Arthur out of hiding to battle the cultists. While Jonah flees, Mirage battles Arthur with his illusions. However, Arthur's training allows him to notice which attacks are mere tricks and which ones are genuine, preventing him from reacting rashly as he did during their previous battle. Arthur uses his Iai-Calibur technique to dispatch Mirage before he can attack an unsuspecting Hinawa, defeating the cultist in a single stroke. Both Hinawa and Arthur advance into the darkness and question who Yona is.
Arthur later arrives to protect a near-fatally wounded Shinra from Haumea. Noticing the devil's injuries, Arthur tells him not to die. While Haumea is mysteriously able to deflect Arthur's Excalibur, she quickly realizes that she cannot control Arthur through her electrical signals due to his ability to control plasma. The rest of Company 8 arrive to protect Shinra, but an earthquake results in the surviving White Hoods fleeing. Company 8 choose to save Shinra's life instead of pursuing their enemies, rushing him to Company 6's clinic for medical attention. While Shinra undergoes surgery, Arthur waits outside the operating theatre with Tamaki and Iris. Worried about Shinra's condition, Arthur peaks inside to check the status of the operation. Only to be shocked by Captain Huang's healing methods. Despite this panic, Shinra recovers a few days later.
VS. Special Fire Force Company 4 arc
Arthur later intervenes in the battle between a possessed Shinra and Company 4 Captain Sōichirō Hague, with the support of Ogun Montgomery. While Arthur is able to see the spirit-like First Pillar, he has no idea how to remove her influence over Shinra. Arthur, Ogun, Hague, and Pan Ko Paat all move to engage Shinra, ultimately Arthur continues the battle alone and promising to kill Shinra if he doesn't snap back to his senses and regain his only admirable traits.
Despite his harsh words, Arthur continues to attempt reason with Shinra by countering his confused arguments for becoming a Devil, much to the First Pillar's fury. This fury presses her and Shinra to rush in to finish Arthur, who counters with a barrage of strikes before finally telling Shinra to embrace being a hero once again to protect what he loves. The First Pillar once again pushes Shinra to kill the Knight, only for Shinra to ultimately break free from her control and reaffirm his faith in heroism.
With the battle over, Arthur and Company 4 attempt to gain a better understanding of the situation. Arthur notes that the members of Company 4 who attacked Shinra were likely controlled by Haumea. As they make their way home, Shinra thanks Arthur for his help and promises to find and protect his brother.
Fifth Pillar arc
While Company 8 deal with the mass outbreak of Infernals and Shinra attempts to protect Inca from Charon, Arthur is ordered to search out and defeat Hauema if she appears because he is able to counter her abilities. After Hauema is spotted by Maki, she uses her Iron Owls to carry Arthur skywards and he attacks her from above. Arthur begins to battle against Haumea who parries his attacks using her electricity. His treat causes Haumea to order Charon to move quickly so they can escape. During her battle with Arthur, Haumea reveals there are meant to be Eight Pillars of the Adolla Burst that the White Clad are trying to retrieve. Haumea orders Charon to retreat with Inca as the Fire Force will be momentarily occupied, before leaping away from Arthur and using magnetism to slow her descent. While Arthur was able to drive back Heauma and tells Akitaru about the Eight Pillars, Shinra was unable to protect Inca and the White Clad are able to collect the Fifth Pillar.
Chinese Peninsula arc
Arthur is part of the expedition to the Chinese Peninsula. Like the others he enjoys the journey and is excited to arrive on Chinese soil. As the make their way through the Tear in Space, Arthur effected by the hallucinogenic fumes common in the wasteland. Although instead of becoming like the others, he simply meditates. This peaceful moment is interrupted by the arrival of a talking mole called Scop who promises to lead them to an oasis if they can save him from a giant sand worm creature. After Shinra and Ogun deal with their new pursuer, the group rest meet with Yata, a talking crow, and take a break for the evening.
The next day Arthur and the others make their way to the Oasis, spotting the Tabernacle and deciding they need to investigate. As the team make their way through the forest and discuss the implications of a Tokyo Amaterasu having an older counterpart, Arthur notices that Shinra's temper flares up and corrects him, wanting to avoid the First Pillar making another bid for control. The group are attacked by Infernal Dogs and Arthur protects Takeru by slaying them all as Tamaki prays for their souls. The team later encounter an Infernal wearing robes who uses a rope trap to bind and burn Licht, Arthur assumes he's dead only to learn Lieutenant Pan shielded him at the last second. The Infernal is joined by its brethren and claim that the Generators, Amaterasu and Tabernacle, exist to bring destruction. Arthur initially disbelieves this, only for Shinra to remember that Giovanni and the White Clad have an interest in unlocking the Amaterasu. Arthur helps to destroy the Infernals surrounding them, defending his quick action as humane, he then joins Pan, Yata and Licht as they enter the Tabernacle because his plasma will allow them to cut through doors or blockades.
Once inside the quartet are sealed within by Tempe's Cult while distracted by stones marked with numbers. Licht says that they should continue investigating and as they find more and more numbered stones and that the numbers are also carved across the hallway ceilings and walls. Arthur quickly realizes that these are the numbers for Pi, something he memorized as a way learning about the Round Table even if he doesn't understand it. In the Tabernacle's heart the group hear the machinery producing a sound eerily similar to human heartbeat. In addition the white arrows nearby, Licht takes this sound as a sign the generator contains a living person, the Lady in Black who created the Oasis and protected the animals. When Pan wants to rush out and check on the others, Arthur tells him not to worry as Ogun is with them. This faith is well deserved as Ogun and Shinra defeat Tempe and his men. Before leaving to return to Tokyo, the teams compare information about the Human Sacrifice and the Women that seem to be inside the Generators.
Haijima Industries arc
Following Joker and Benimaru's investigation into the Holy Sol, Company 8 decide they need to investigate Haijima Industries. Arthur wished to storm the offices for information but this plan is quickly rejected as Haijima's nation-wide operations makes impossible to mobilise against without explicitly knowing what target. Knowing that everyone is connected to Haijima somehow, Arthur begins to think he might be a suspect and teases Shinra about his childhood ties to the organisation. This bickering is interrupted by Inspector Licht calling a team meeting, where he reveals (to little surprise) that he was a spy for Haijima.
As Shinra and Licht infiltrates the Power Development lab, Arthur with the rest of Company 8 wait on standby in case of danger. When Nataku's Adolla Burst starts to manifest during Shinra's bout with Kurono, Victor Licht reports this to Captain Obi and Vulcan takes this as a sign to storm the building. Arthur remains unperturbed as the Matchbox is overturned by a tiny robot and he leaves fighting the Puppeteer to Maki and Vulcan. Deeper into the facility Company 8 come across a giant wave of smoke emanating from a doorway. Arthur's surprise is interrupted by Kurono Yūichirō chasing Shinra and Licht out the building while carrying Nataku. When Kurono see Iris and Tamaki, he attacks them but is countered by Obi and Arthur's defence. As Kurono explains his motivation, he is interrupted by Charon of the White Clad attacking form a rooftop.
As the White Clad capture Nataku, Arthur is hopeful that Kurono and the White Clad will fight each other to the point of exhaustion. Unfortunately the bout of common sense fails to Account for Kurono's insanity and devotion to hurting the weak, as he completely ignores his objectives and tries to attack the two Sisters again. Arthur manages to hold the Reaper at bay despite long enough for Kurono get tired so duelling worthy opponents, forcing him to target the White Clad abducting the Sixth Pillar. Arthur and Shinra manage to grab the boy and attempt to get him to safety but are stopped by Inca's explosion.
Ritsu of the White Clad manages to convert the ashes of the cultists Kurono killed and an Infernal to create an artificial giant infernal. Her plans are disrupted by Haumea using her powers to heighten the boy's aggression and lower his inhibitions, causing him to wildly attack everything in sight and his radioactive powers begin o endanger everyone in the area. While Shinra and Charon work together to bring Nataku under control, Arthur is called away by Vulcan to use his to plasma to stop Haumea's meddling. Tricking Arthur into believing that placing Excalibur into a special generator will be an important part of a knight's duty, Vulcan manages to simulate a electromagnetic pulse, shutting off surrounding Haijima technology and blocking Haumea's signals. The two need to keep avoiding Arrow's attacks and keep Haumea in range while she battles the Puppeteer, with Vulcan hoping Shinra and the others fix things before Arthur realises he's been tricked.
The combined efforts of Kurono, Shinra and Charon end up being enough to stop Nataku. Exhausted and acknowledging Kurono's compatibility with Nataku, the White Clad retreat. In the Aftermath Company 8 forges an uneasy alliance with Haijima against their shared enemy.
Operation Nether Investigation arc
Arthur appears in this arc.
Arthur joins Shinra in Asakusa to learn about Hysterical Strength, where they are greeted by Konro at the Guardhouse. Once they find Benimaru, they are joined by Tamaki who wishes to improve after falling short in pervious battles. While Tamaki trains with Hinata and Hikage, Shinra and Arthur find themselves confused and subjected to many different rituals including being tied upside-down to a stake or being dragged through the street. Benimaru explains this is necessary for them to learn Superfire and he went through the same thing, although he latter confesses he has no idea if any of these exercises were relevant or just hazing rituals.
After enduring Asakusa's madness to the point of exhaustion, Shinra and Arthur are furious to learn that Benimaru is not sure what the point of that was. As such, they strike with genuine fury and anger when Benimaru starts sparring with them. Feeling their violent intentions, Benimaru response by viciously overwhelming Shinra and Arthur as their uncontrolled rage feeds his own. Having taught them the value of life, the Breath of Life, Benimaru plans on teaching them the Press of Death. The boys fight their teacher for 5 hours before being completely exhausted and overheated. Benimaru tells them that the actual training starts now. Benimaru continues his rigorous training with the Company 8 newbies, much to Tamaki's discomfort at them Overheating. Reaching his limit and continuing to fight, Arthur reaches deeper within himself and masters his survival instinct to awaken new power. An experience he latter compare to feeling like an important save file was being deleted.
Ōbi's Rescue arc
Learning that Akitaru was arrested by Tokyo Army, and that they were in league with the White-Clad, Arthur and his brigade decide to rescue him at the cost of being branded traitors to the empire. Viktor takes the brigade to Joker, leading to the criminal taking the fire soldiers to his underground secret base. The group quickly mobilize to save Obi with Shinra and Joker going ahead while the other catch up. Arthur is initially part of the second wave but falls out the back off the truck after ignoring safety warnings. He rushes on foot and arrives in time to defeat Stream with one slash.
Dragon, the final remaining Butcher, finally arrives at the scene. Dragon's name, inhuman arrogance and powers all excite Arthur to reach new heights of strength. The Butcher withstands the attack before Arthur away. Easily withstanding more of Excalibur's attacks and Hinawa's gunfire, Dragon breathed more flames, and forces Arthur to defend himself using his Plasmantle. While Arthur appears to be dominating the fight, Dragon's scales actually cause those who attack him to be injured while he remains unharmed. Arthur increases the size of Excalibur using his delusions and the support of his friends: he swings his "Dragon Killing Holy Sword" at Dragon, only for Excalibur to shatter. He collapsed to the floor utterly defeated and falls into unconsciousness. Company 8 is ultimately saved by Benimaru Shinmon and Arthur is carried to safety.
Arthur's Adventure arc
Following his crushing defeat, Arthur remains depressed while clutching the shattered pieces of his sword. His mood improves once Vulcan tells him they can forge a sword out of legendary metal that will be able to slay any enemy the King Knight faces. In reality, Vulcan is leading Arthur on a wild goose chase so that his delusions will make his new blade and abilities strong enough to fight their enemies. Arthur, oblivious to this and misinterpreting several key events, decides he must descent into the Neverworld to attain his true power. Much to his party's frustration.
Abandoned by his family a second time, Arthur vows to never lose again.
Stone Pillars arc
Arthur appears in this arc.
Unlike the other members of Company 8, Arthur does not join the battle against the White Clad forces. He sits alone in the battlefield to conserve strength for his inevitable rematch against Dragon. He almost intervenes when Ogun begins to struggle against Charon but Ogun tells him to remain in place. Dragon arrives with an explosion that throws the Infernal way in all directions after Charon's defeat. Arthur stands and their duel begins. Impressed by Arthur's new blade and improved reflexes, Dragon praises him as a swordsman capable of cutting through anything (except a Dragon) before attempting to crush Arthur with a pillar of flame. Arthur leaps into the air to escape and avoids the second attack by using Violent Flash and airborne rubble as steppingstones. He manages to strike his target but is set flying back to the ground by Dragon's counterattack. As the battle drags on, Arthur scores countless lethal blows against Dragon but fails to hurt him at all. His confidence starts to break as he realizes just how impossible a task it is to slay a Dragon. Dragon notes that Arthur is now struggling to stand under the weight of his own despair as the final cataclysmic begins. Losing all interest in both the battle and world, Dragon leaps into the air. This allows Hinawa and Maki to redirect Charon's dying attack towards the Butcher and blast him into space. With the battle temporarily paused Captain Obi manages to rally the Company and inspire hope in the face of overwhelming distraction. Arthur, confident Dragon will return, asks Vulcan for his support in becoming even stronger.
Returning to Company 8's cathedral, Arthur and Vulcan venture inside. Arthur decides there is one final trail he must pass: he must complete Dragon Question on Super Mintendo. Vulcan, completely baffled by this, decides to do his best and helps Arthur play strategically and progress to the game's ending. Once they reach the final dungeon, Arthur thanks Vulcan for being by his side and continuing to remain calm in an insane situation. Arthur turns the conversation toward Yu's fate and Vulcan opens up about his sadness, fear and disgrace about failing to save his family. Comforting his crying friend, Arthur promises to save Yu. Instead of completing the final boss, Arthur goes outside to find Yu.
Handling Vulcan his blade, Arthur tells him that pointing it to the sky while thinking of his love for Lisa and Yu will let the Holy Blade point them in the right direction. Going along with is, Vulcan is shocked when this actually works. While still baffled by how this is happening when the tool has no such feature and he has no powers, Vulcan is grabbed by Arthur who decides to teleport them to Yu's location. Somehow, this is actually possible and the duo appear directly behind Giovanni, who is using Yu's body as a vessel following his defeat. While he rambles about his victory, Giovanni is pierced by Excalibur's blade. Arthur's control being so precise that he is able to destroy the Bug controlling Yu's brain without harming the boy. With his side-objective completed, Arthur looks on as the horizon explodes into pure light as Dragon re-enters the atmosphere. Realising that Dragon's despair is so great that he is able to drag the world towards the ruin he craves. As Dragon roars for Arthur to face him, the Knight gets ready once more.
Arthur appears upon the volcano near to Tama Bay. Vowing to free Dragon from his despair and save the world as the battle starts. When Dragon knocks Arthur into the air, the knight hides in a thunderstorm to draw the energy into his blade and cuts Dragon deeply enough to draw blood. Dragon is overjoyed, finally acknowledges Arthur as a person and opponent before continuing the fight. Arthur launches a counterattack to Dragon's flame, forcing Dragon to block for the first time in his life before hammering the Fire Solider into the ocean. Dragon pursues Arthur into the depths, countering Arthur's electrical shocks by splitting the sea itself. Declaring the world is too small for them both to exist both him and Arthur to exist. The battle continues with each opponent pressing the offensive as hard as they can. Arthur manages to knock Dragon back into the thunderstorm above. Unleashing Violent Flash: Eight-way Slash, Arthur's attack slits the clouds and cuts pen Dragon's belly. In his joy, Dragon transforms into an armored state and uses his newfound speed to regain the advantage. Exploiting an opening, Dragon grabs Arthur and flies them out of the atmosphere and crashes on the Second Moon.
Being unaware that space is a vacuum, both fighters continue with some immunity to the side-effects of oxygen deprivation. Although Arthur quickly collapses. Dragon turns to leave in disappointment. Only to see signs that Arthur has equipped a Star Ring. Turning, Dragon sees rising once more, standing atop the text he imagined and made real through Adolla when he equipped his ring. Using Adolla's power again, Arthur is able to create a stronger Plasmantle and begins the battle once more. In the void of space, Arthur continues his relentless assaults as both knight and dragon use the stars as stepping stones for their duel. The pair ultimately simultaneously impale each other. Refusing to falter, Arthur continues to attack, severing Dragon's hand at the cost of his eye before driving the beast to the ground. To protect his remaining eye from Dragon's flames, Arthur sacrifices his left hand. Swearing to keep his oath to Vulcan and to also return alive, Arthur continues to fight. With stars shattering around them and running out of options, Arthur realises that his desire to survive is asking too much. Deciding the awareness of death he learned from Benimaru is not enough: Arthur mentally prepares himself for death and one final attack.
Realising that he cannot defeat Dragon without getting close, Arthur charges for his final attack the tells Dragon that they should enjoy this fight to the end. As Arthur leaps towards him, The Dragon unleashes a torrent of flame as Arthur leaps forward. His body engulfed by flames burning away his lower body, the Knight King grins and swings his blade downwards. Unleashing Violet Flash: Earth Divider to completely bisect Dragon down the center, the slash continues beyond the limits of the moon and cuts through the Eye looking down on Tokyo and the despair coating the entire world, extinguishing the fires of cataclysm. As the fighters float in space a disintegrating Dragon praises Arthur for slaying an immortal and embracing hope right to the end. Arthur smiles as Dragon tells him that he's happy they met before vanishing completely.
Alone in the void Arthur shouts down at the Earth, at Shinra, declaring himself The Knight King and ordering the Devil to finally become the Hero. Contemplating how many injuries he sustained and if recovery is possible, Arthur gazes up at the sun. Deciding that Shinra can be trusted with the rest, Arthur Boyle smiles as he closes his eye and lets go of Excalibur. But since a weapon such as Excalibur is bound with such strong feelings, somehow it returns.
- Both King Arthur and Excalibur are inspired after a British medieval leader and his legendary sword.
- Arthur also has a similar physical appearance to Soul Evans from the Soul Eater series.
- Arthur was first seen on the cover page of Chapter 0, despite not debuting until Chapter 2.
- According to his Character Profile in Hero or Devil:
- Arthur's favorite food is royal court cuisine (which he hasn't tried before) and ramen from Ippudo Ramen, while his least favorite food is horse meat sashimi.
- Arthur's favorite music is court music (he has never heard any).
- Arthur's favorite animal is a horse.
- Arthur's favorite colors are white and blue.
- Arthur prefers people with glass shoes and tiaras.
- The person Arthur respects the most is King Arthur.
- He has trouble around no one and is afraid of no one.
- Arthur's hobby is making castle models, his daily routine involves sword practice and his dream is to become the Knight King.
- Arthur's foot size is 26 cm and his eyesight is 1.5.
- Arthur's favorite school subject is physical education, while his least favorite are the ones that involve a classroom.
- In Chapter 303, it's revealed that Arthur is the original owner of Excalibur from the Soul Eater series, making him the famous King Arthur of legend.