This is the article on the weapon "Demon Sword". If you are looking for the article on the third chapter of Eiyū Kyōshitsu "Demon Sword", head to Demon Sword.

Mini form | Sword form | True form

Miniature Asmodeus








The Inferno


Cursed Sword


Arnest Flaming


Manga: Chapter 1

Asmodeusアスモデウス Asumodeusu」 also known as the Demon Sword, is a Cursed Sword that has been passed down through generations of the House of Flaming. The sword has it's own will and could materialize and manifest itself as a highly powerful demon. The sword is currently carried by Arnest Flaming.[1]

Due to his actions and major aspect, he could be considered as the main antagonist of the Asmodeus arc.

Blade Portal



Asmodeus, as a sword, has a unique design. Its edges are waves composting to the bevels, with the flat contrast between the two individual halts in steel. The halt almost connects to the two large and oddly shaped points of the symmetrical blade leading to cross stamped middle that protects the wielder while their hands rest on the leather handle. It's sheath is also composed of black leather with bronze finishing.[2]

True FormEdit

In his true form, Asmodeus poses as a giant demon, being roughly 4 times larger than an average human. He has a fit and ripped human physique and human like features, with the exception of a few cracks and nerves spread across his face, most notably from his eyes and to his upper skull. He also has two horns extending out from both sides of his head which curve upwards, and is usually surrounded by black, mist like aura, similar to his mist form.[3]

Mini Form (Current form)Edit

After Arnest successfully managed to control the demon, Asmodeus now has the physique of a child, being very tiny compared to his true form while still retaining his facial features, which only toned down a little, and the nerves and cracks on his skull vanished. His horns grew drastically shorter and he still is surrounded by black, mist like aura.[4]


True FormEdit

Asmodeus is arrogant and confident while in his true form and mist form, sadistic and barbaric to say the least. He's very confident in his power and truly believed that Arnest will never be able to overpower him. However, he gets angered when looked down upon and would not hesitate to use force in order to prove his views.

Mini FormEdit

After Arnest managed to overpower the demon, and he underwent a physical change, Asmodeus became more domestic and not as egotistic as he was in his true form. He speaks to Arnest normally, despite constantly pointing out to the latter's disrespect to him.[4]


House of FlamingEdit

Main Article: House of Flaming

Asmodeus completely and utterly despises the House of Flaming, blaming them for his sealing and usually badmouths them. Due to his power, he was sealed away in a locked room of the house and was there until Arnest released it, consuming the girl and causing her to commit a massacre that went down in the house's history. It was said that the sword has been passed down through generations of the family, but only changed the hair color of the very first head of house upon possession, later doing the same to Arnest. He still hates them and is prepared to fight them with all what it takes to gain his freedom.

Arnest FlamingEdit

Main Article: Arnest Flaming

As a Flaming, Asmodeus has hated Arnest since the very beginning, never abiding to what she says and always trying to get her to do as he wishes. He considers Arnest a weak obstacle on his way to freedom and always tries to consume her whenever the time is right. He also sometimes orders her to some things which she does not approve, and is sealed back in, like when he told her to kill Blade. It was clear that Asmodeus does not see Arnest as his master, and considers her body to be his servant which he would use to bring upon havoc and destruction, but was eventually defeated due to Arnest's strong will. After the liberation, Asmodeus seemed more accepting of Arnest as his master, but still keeps an arrogant attitude towards her.


Main Article: Blade

Asmodeus's very first thought of Blade was that he posed a great threat, and that he should be eliminated immediately after Blade pointed out that the sword is cursed. Like Arnest, he seems to hate Blade, as while he possessed Arnest, she attacked Blade without any second thoughts.


Asmodeus is the treasure of the House of Flaming, as it has been passed down for generations, from ancestor to another. It was the blessing of the house while it was sealed. The wielder of the sword becomes the next head of the House of Flaming. The sword's curse sometimes turns it's wielder's hair to red or vermilion in Arnest's case.[5]

Asmodeus is able to manifest itself before the wielder in a form of black smoke or mist, and speak to them, though it is unknown if others can see and/or hear it as well in that state. However, once inside the sword's inner world (realm), the demon Asmodeus manifests himself in his true form. The demon would entirely possess the wielder if they don't have an iron will to fight it, something that the Flamings' conveniently developed.[1]

Asmodeus Sealed

A sealed Asmodeus


Asmodeus has been passed down through generations of the House of Flaming, the last being Arnest. It was sealed for an unknown period of time before Arnest released its seal and became the new owner.[5] The sword was chained inside a dark room somewhere within the Flamings' household.


Transfer Student arcEdit

Years later Arnest is seen carrying it around with her all the time. While she is in the restrooms, it manifests itself to her only to be quickly sealed back in. The sword raises Blade's suspicion and he asks Arnest about it, only to be turned down by the latter. The demon appears to her again and tells her that they should dispose of Blade because "He's dangerous" but Arnest calmly defies it and the demon disappears once again.[6]

Asmodeus arcEdit

With the Tournament King has arranged, Arnest is forced to use the sword to fight Sophitia Femto, a fellow Top Grade student. After delivering a black energy ball to conclude the fight, Arnest calls out for her next challenger which is Blade, and as she is speaking to him, Asmodeus, finding an opening to act, consumes the girl, dragging her to his inner world (or realm as he calls it). He asks Arnest if she needs his power again and tells her to submit to him, but Arnest refuses and tells him that she will not allow him to use her again. The demon then grabs her by the neck, strangling her and telling her that the way she is now, she is no obstacle for him. Arnest regained consciousness soon after.[7]

The following day, Arnest at the Royal Library of Banned Literature requests for Asmodeus to consume her, which the demon accepts and drags her to his realm. There, Asmodeus welcomes Arnest in his true form and tells her that they will finally settle this.[8]

Seemingly annoyed, the demon asks if Arnest is truly serious about trying to control him, which the latter confirms. He tells her that he exists solely for destruction, murder, bloodshed and that her body only exists to execute his commands, and proceeds to curse Arnest and her family for sealing him all these centuries. Arnest offers him a deal, that he can do whatever he wants when she allows it at times needed but Asmodeus quickly disregards that offer, repeating the meaning of his existence. Arnest then provokes him only to find herself desolving while the demon laughs, telling her that she's too weak and continues to consume her entirely.[9]

A possessed Arnest then attacks Blade outside whilst she struggles to find herself inside. Seeing her slight vision of hope, Asmodeus tells her to stop thinking, for it is all futile, ordering her to stop resisting and bind to his will. However, with her strong resolve and eagerness to see her only friend again, Arnest overpowers the demon's will and finally manages to control him and the sword.[10]

The next day, while Arnest is getting ready to leave for school, a now miniature Asmodeus tells her that she will be late. She tells him that she will not respond to him in public since she is the only person who can see him, and that she'll seem weird if she does, much to the demon's displease. He asks her why she's not putting her hair up like usual and Arnest tells him that she prefers it this way for the day.[4]


Asmodeus original sketch

Asmodeus's original sword design

  • Asmodeus's name is a clear reference to the mythological King of Demons, Asmodeus.
  • It's possible that the sword took a special liking to Arnest as she is only the second wielder of the sword to have their hair color changed.
  • In a recent popularity poll by Shin Araki, Asmodeus ranked third for the most popular side character, with a total of 8 points.
  • Araki has provided the original sketches of Asmodeus's sword form design, though it is not very different from the current one, the waves and edges of it were not as sharp as they are now, and the point edges of the hilt were slightly longer.


  1. 1.0 1.1 Eiyū Kyōshitsu MangaChapter 3 (p. 1-8).
  2. Eiyū Kyōshitsu MangaChapter 3 (p. 5).
  3. Eiyū Kyōshitsu MangaChapter 5 (p. 25-27), Asmodeus appears in his true form.
  4. 4.0 4.1 4.2 Eiyū Kyōshitsu MangaChapter 6 (p. 21-22), Asmodeus's miniature form.
  5. 5.0 5.1 Eiyū Kyōshitsu MangaChapter 3 (p. 3 - 5), Arnest's hair shifts colors
  6. Eiyū Kyōshitsu MangaChapter 2 (p. 27-29).
  7. Eiyū Kyōshitsu MangaChapter 4.
  8. Eiyū Kyōshitsu MangaChapter 5 (p. 21-26).
  9. Eiyū Kyōshitsu MangaChapter 6 (p. 1-10).
  10. Eiyū Kyōshitsu MangaChapter 6 (p. 11-17).