Asmodeus arc

Asmodeus arc is the second arc of the series, beginning from chapter 3 and ending at the 7th and final chapter.

Overview
With the demon sword Asmodeus gradually setting loose and out of Arnest's control, Blade who notices the bizarre ambiance around Arnest and the sword, decides to help the female in liberating herself from the sword's curse. As such, Blade visits the Royal Library of Banned Literature and acquires the information he needed in order for Arnest to begin a ritual that would help her confront the demon, and can only hope that she defeats him without losing control of herself, which would lead to Blade killing her as agreed.

The Burden of a Flaming
12 years ago, a curious Arnest wanted to see the treasure of her house, deciding to steal the gates' key from her father and enter the room where the sword was sealed away. It was then that she first acquired the cursed sword Asmodeus and became its wielder, subsequently becoming the next head of the House of Flaming, going berserk as soon as she made contact with the sword, which lead to her killing many of the house's residents and servants.

While training at the school, Arnest recalls her past and decides to take a break by visiting the cafeteria, where Blade sits with her as opposed to all the other students. Though annoyed, Arnest tells Blade that he is better than her, and far stronger, and confesses that she had her doubts about him and also tried to frame him for the criminal she assumed he is. But, due to Blade's ignorance and rather infuriating nonchalance, and the former soon leaves the table all flustered after Blade calls her his "friend", claiming that he is her very first friend when a student storms into her room as she told her earlier, takes the documents and leaves as quickly as she came.

The following day, the King has arranged a tournament with the grand prize being the winner having a chance to fight the legendary hero, hinting that Blade is indeed the hero from the legend. which annoys Blade greatly. The tournament begins with Blade gaining an easy victory over Leonard, whom he defeated in a single punch. At the same time, Arnest was exerting herself as opposed to usual while fighting the mysterious Sophitia Femto, who was capable of fighting Arnest on even grounds. Their clash was intense, even damaging the earth itself and causing massive shock-waves. However, as Leonard has noted, Arnest gained the upper hand and manages to defeat Sophie after launching a black energy ball at her, for an instant win. After her fight with Sophitia Femto, Arnest was scheduled to have a match against Blade, however Blade refused as Arnest was heavily fatigued while he has barely consumed any energy at all, which infuriates Arnest, who, and after exerting herself greatly, is consumed by the demon sword's spirit and passes out.

Preparation for liberation
Later, Arnest wakes up in the school's clinic, and is surprised to find The Doctor flirting with Blade behind the curtains. Blade innocently asks if she is okay, but is treated with a punch to the face instead. Quickly following the girl, he tells her that it was a misunderstanding, however Arnest merely thanks him for not telling anyone of what happened at the field before leaving. Blade then sensed King's presence and calls him out, asking how long he's been there, which King responds to by teasing Blade that he was rejected by Arnest, aggravating Blade more. However, once Blade asks about Arnest, which the King teases him more about, he tells the boy that he is not willing to give away information about his students so easily, and that Blade will have to find out on his own. To investigate the sword, Blade goes to the Royal Library of Banned Literature, facing the Library Guards who seemingly recognize him as "Hero Blade", Blade correcting them that he is "Former Hero Blade".

After defeating the Library Guards, Blade surfs the Library's directory, seeming perplexed, however he quickly rushes to class where Arnest was, after seemingly acquiring the information he needed, asking her to come with him and Arnest takes him to her room. There, Blade asks her to tell him about what happened in her past and how she first wielded Asmodeus, and Arnest tells him everything about her past with the sword. When she speaks her fear of going berserk again as she did before, Blade tells her that he will simply kill her if that happens, and Arnest does not protest against that idea, calmly accepting death. The boy takes Arnest to the Royal Library, which Arnest hesitates to enter as it is royal ground, questioning what type of friendship Blade and the King. Blade draws a magic circle on the ground, which Arnest enters and begins the ritual, forcing the demon sword to consume her, and prepares to fight him.

The girl's liberty: The Demon Sword's defeat
Inside Asmodeus's world, finally confronts the demon, who is not only annoyed by her presence, but does not show the least bit of fear of her. Arnest asks him why he does what he does, and Asmodeus responds that he exists solely to bring forth destruction. However, when Arnest realizes her position, she offers the demon a deal, that he can bring forth as much destruction as he wants, but only when she engages in battle. As expected, Asmodeus refused, telling Arnest that she is too weak to be his order, and that he never found her a threat at all, proceeding that she is merely a vessel for him to use for his own will. Arnest releases a rather nervous laugh before mockingly asking if the demon is a male, as all males would always buff out their chests in bravado, which annoyed the demon who instantly consumes the girl, forcing her outer body to release a boisterous roar and attack the anxiously waiting Blade. Though he manages to stop her attack, Blade ignorantly asks what happened, but Arnest does not respond.

Inside, Arnest is engulfed in darkness as the demon gradually takes full control of her. Losing all hope, she begins to reminisce all her time at the academy, and how she has no one to return to. But, as she recalled her days, she remembered Blade, whom she described in great detail, saying that he lacks proper manners and the necessary intelligence, yet he's inevitably her very first friend. She remembers that he is also waiting for her outside, and that he believes in her ability to overcome the curse, which sparks a light of hope within her. Screaming her name, Arnest wakes up in Blade's arms, asking how she ended up in such a position with Blade simply explaining that he did what he had to do, thanking the latter for his support. The next morning, while preparing for school, Arnest is reminded of her early class by the now miniature Asmodeus, whom Arnest disregards much to his dismay, before heading to school with a new hairdo, finding Blade awaiting for her at the gate.

I can hear his voice.. I've got him.. I must return, to where the person who believes in me is.. I'll fight.. This is my decision. Because this is my fight. I'm not alone. There's nothing binding me. I am... me. MY NAME IS ARNEST FLAMING!!

Following those events, she changes her hairdo and heads to school, which was the first thing Leonard noticed, commenting that she almost seems like a completely new person, or even, "a damn cute girl". A confused Blade asks what he's talking about, and when Leonard says that she changed her hair, Blade says that he's seen her before like that in the bathroom, finding a knife darting towards him thrown by the annoyed Arnest. Surprised by her casualty, Leonard questions how she could be throwing knives at people so nonchalantly, while Blade jokingly comments on the situation. Arnest asks if he finds the new hairstyle fitting to her, which of course received a rather unsatisfying response from the hero, who says that women's hair looks weird to him. A snapped Arnest tells Leonard that she will take his offer now, and begins to throw tens of knives at the escaping, overly joyful Blade, who does not consider it a threat whatsoever, while Arnest runs after him and scolds the mini Asmodeus.

Events

 * Blade vs. Leonard: Blade defeats Leonard in a single hit during the tournament held by the King.
 * Arnest Flaming vs. Sophitia Femto: Arnest and Sophitia face off during the tournament held by the King, where they fight on even grounds.
 * Blade vs. Arnest (Tournament): Cancelled.
 * Blade vs. Library Guards: Blade fights the Library Guards in order to enter the deepest parts of the library.
 * Arnest Flaming vs. Asmodeus (True Form): Arnest confronts the demon who's been the cause of her trouble and agony, finally getting a chance for retribution.
 * Blade vs. Arnest Flaming (Possessed): Blade is forced to fend off the berserk Arnest while she fights the demon inside his world.

Story Impact

 * Arnest's past is revealed.
 * Asmodeus is finally defeated and returns to his miniature form, and no longer attempts to consume Arnest, instead accepts his inferiority.
 * Blade is mentioned several times to be the "hero" of the legend.
 * This is the final arc to be featured in the manga.
 * Sophitia at the last panel of the last page of chapter 7, the final chapter, is foreshadowing of her being the main heroine of the second light novel volume.