Mahiru-no-Yo

Mahiru-no-Yo「真昼ノ夜, lit. Midday's Night」is a possession-type demon of the Black Demon series which is Guren Ichinose lover former human, Mahiru Hīragi she is sealed within a sword and became Guren Cursed Gear.

Appearance
Mahiru-no-Yo appears exactly as Mahiru herself with the exception of having fangs and red eyes being a former vampire, she is the only demon who doesn't have pointed ears or horns unlike the others. She still wears her sailor fuku uniform of First Shibuya High School.

In her sword form she is colored as black katana have a glowing crimson, red streak that is outlined down in the middle portion.

Personality
Mahiru-no-Yo is Mahiru herself but since her humanity is gone and turned into a possession-type demon makes her particularly violent and the fact that she tells Guren to listen to her only but also helps Guren grow into a namanari and possesses him as needed to make Guren's demonic side take control.

However Mahiru doesn't appear to be as twisted when she herself became a namanari as she is able to keep calm and make rational decisions and unlike other demons who take desire from their host to gain more power, Mahiru doesn't use those methods, she also appears to still love Guren.

History
Mahiru-no-Yo was actually Guren previous demon, when Guren threw away Noya, Mahiru picked it up and stabbed herself with it in the heart and integrated with it, as Noya was unable to stop the curse from spreading, since Mahiru had planned this all along eventually Mahiru was sealed/fused by Noya thus transforming her into Mahiru-no-Yo. She became the demon within his Cursed Gear and part of the Black Demon Series.

Second Shibuya High School Arc
When a vampire escape the school grounds Guren uses Mahiru-no-Yo to slay it. Later when Kimizuki arrives in Guren's office and asks him if he can receive a demon weapon, Guren intimidates him by showing him his demon aura as it fills his office. In chapter 6 Guren arrives at the classroom and attacks, unleashes Mahiru-no-Yo demonic aura that sends most of the class tumbling to the floor, many of whom go unconscious without those with willpower to withstand it, Shinoa manages to remain fine because of her immunity to all demons, and Yoichi is completely unaffected by the attack to the point where he does not even feel it. Yu and Kimizuki manages to withstand the demonic aura though they tremble.

Shinjuku Arc
At the Shinjuku 5th Street intersection, He later uses Mahiru-no-Yo to slay several vampires before confronting Mika and Ferid.

Post-Shinjuku Arc
When Shinoa goes and meet Guren at the lab underground he mentions her sister Mahiru  invented Cursed Gear, and that sacrifices are necessary.

in chapter 17 Guren meets with Mahiru in mind much to her happiness.

Guren challenges Yu to a fight to test him for the next step of mastering his demon, in the fight Guren orders Mahiru to possesses him and overwhelms him. After Shinoa heard Guren calling out his demon name, Guren calmly says he would let Shinoa kill him while holding her scythe at his neck. Shinoa asks him if that is his way to atone for killing her sister, unbeknownst to her that Mahiru stabbed herself by Guren previous demon. She asks if she is in his sword since she heard him call her name. Guren says that Mahiru is already gone since she turned into a demon and saved the world by completing Cursed Gear.

Shinoa asks him if Mahiru is together with him inside his sword, stating that he is being possessed by her. Guren asks her if she and Mahiru ever got along. She asks if making use of Yu was one of Mahiru's orders and asks if her sister or the demon for lack of a better world that is inside his sword is ordering him, saying he is the one in control.

After discussing the events of 8 years ago, afterwards in chapter 23 she appears and whispers to Guren to only listen to her after talking with Kureto.

At the Ebina rest stop Guren punishes Shinoa squad, in the fight against Yu Guren releases a powerful red whirlwind from his demon destroying the doors and knocking off Shinoa and Mitsuba after the fight Shinoa charges at Guren only for her demon to get knocked off using Mahiru-no-Yo. After defeating Mel Stefano he goes on to his next target to his list Thirteenth Progenitor Crowley Eusford. Chess Belle and Horn Skuld. When Crowley was overpowering him he released Mahiru-no-Yo by in the ceiling by calling out it's name releasing dark crimsion sparks.

In chapter 38 Guren gets captured by the vampires after the fight with Crowley he was seen near Krul Tepes and a few of her soldiers. He was being beaten by a noble, the angered noble grabs Guren by the hair and raises up his face, when Guren spits on his face the vampire curses him and kicks him to the ground threatening to kill him.

At this point Guren personality began to change as Mahiru possess him and turned him into a namanari, easily beheads the noble, the sword seems to have a will of it's own as it unsheathed itself. Guren personality would change into more demonic and heartless. In chapter 40 Guren arrives at the airport in Nagoya where the experiments are being held by Kureto. Guren raises up his sword, and chains wrap around his arm as the curse consumes him speaking the words to drink the blood of human sacrifices, demons, and the progenitor turning Mahiru-no-Yo from black to complete pure red color similar to first-class vampire weapons.

Guren then slaughters both vampires and a humans confusing everyone except Kureto,

After Yu stops the demon Abaddon, Guren still possessed by Mahiru, tells Yu to do it and break their taboos. As Guren chases Yu, Shinya stops him and asks him about betraying so many of his men before realizing Guren has been possessed.

Post-Nagoya Arc
After three months time skip Guren and Kureto can be seen walking and fighting together side by side against the vampires with their demon weapons. While so, both men commanded their respective demons to attack the enemies before them On his way back to Shinjuku, Guren injects the drug into his forearm while a soldier drives him. The drug suppresses his demon.

Osaka Arc
In chapter 54 while Guren driving with his squad he recalls eight years ago on December 25, where he was willing to bring about the Apocalypse in order to revive his friends and be with them for only ten years, Mahiru manifests and warns Guren that if they found out the truth that they are originally dead, they will turn to dust, Mahiru leaves after Guren tells her to Mahiru goes to the roof of the car where she gets confronted by Byakkomaru. He demands for Mahiru to identify herself as she is not a demon, and when she asks him what he is going to do about it, Byakkomaru says he will do nothing unless she harms Shinya. Mahiru claims that she will kill Shinya if he knows about her and that Byakkomaru should just shut up. Mahiru goes ahead of the squad to Osaka. She smells the scents of Shinoa and burning vampires which leads her to go investigate the latter scent. She appears right in front of an unsuspecting Ky Luc before turning her attention to the burning crosses holding Ferid and Krul, she taunts Ferid suffering which causes him to notice her.

In chapter 55 Despite Ky Luc unable to see her he had 'bad feeling' he tries slicing it but he leaves her be. Mahiru later waves at Guren as he tries to run her over. In the following chapter after arriving at Ferid mansion Guren knocks his squad using Mahiru-no-Yo except for Shinya who manages to hold himself off Mahiru manifest next to Guren, where she comments that Byakkomaru is looking to kill to him, which Guren says it's because she provoked him; as well as becomes annoyed with Mahiru's comments before the fighting starts.

Guren wins the fight and appears infront of Guren ignoring her questions of bringing his squad, she soon realizes Guren is nearing his complete transformation into a demon. When Guren tells her to leave him alone, she reminds him he can do it whenever he wants to. She appears in front of Shinoa and is glad she is doing well, though she wonders as to why she can't see her. She realizes her demon hasn't awakened yet. She goes on to say that love, more specifically sexual desire and lust, will corrupt Shinoa until she no longer cares about the world. She looks at the gathering squad and notices that she has her sights on Yu. Mahiru leaves saying how much she enjoying this.

The following chapter she appears beside Shinoa and and frowns when she sees Shinoa feel a pain in her chest, when Guren spoke about the being that's been controlling the Hīragis.

In chapter 61 Guren summons Mahiru-no-Yo to attack Ky Luc recalling his uneasy feeling.

Forms and Abilities

 * Demon's Thrall: Mahiru-no-Yo may enter her host's mind and consume him with illusions in an attempt to break his will. If she wins, she gains control over his body.


 * Basic Form: Mahiru-no-Yo appears as a black katana with a red streak down the middle. Merely drawing her increases her bearer's physical abilities significantly and calling upon her name increases them tremendously

"When Guren spoke of drinking the blood of human sacrifices, demons, and the progenitor his katana drastically underwent a sudden change of color scheme. Through doing so, the katana itself went from being almost black in color to purely red of all blade length similar enough to vampire fire-class weapons used by the progenitors drank their blood. Not only that but something similar when Guren used a talisman to turn the color of a non-cursed gear's blade crimson from the light novel series, in the anime however he managed to turn his demon into completely from black to fully red without using or placing some talisman on it."
 * Namanari: A human one step from becoming a demon. Mahiru-no-Yo has managed to turn Guren into one of these. In this form, Guren and Mahiru cooperate and have tremendous power. However, Guren's personality changes to a more demonic, heartless, and demanding one. It is unclear whether this is the demonic side of Guren that Mahiru began to create the summer before the Apocalypse when they were both human or if Mahiru is the one in control of Guren body.038.jpg"Once Guren is possessed by Mahiru-no-yo, the blade would seem to have a mind of its own. The blade unsheathed itself from the scabbard and then proceeded to move around on air swiftly, beheading the noble vampire. In the manga, it was right after that did Mahiru appear as a ghostly apparition with mass-like demonic aura, hovering over Guren while his katana is equipped under her."
 * Anime: Guren would go on and further use the power of his demon weapon, Mahiru-no-Yo to summon forth a red whirlwind cloaked with thin layer of crimson-like demonic aura. More so, the demonic aura can be seen concentrating all around its inner layer and then being destructively launch at targets through him upfront within his range. This red whirlwind was able to demolish the concrete wall of a building, pushing even half Shinoa squad.
 * Mahiru-no-Yo can also be used to devour an enemy's attack. If Guren was on the defensive side, he would then call on the demon blade's name to assist him in battle when he was knock far back and being sent flying to the ceiling. He will then used the demon's power and ability to cushion his physical impact for safe landing.
 * Mahiru-no-Yo can significantly increase Guren's physical abilities, and calling out her name would increase his power even more so. If Guren wishes to, he can invoke the demon's real name to have her possess him. This would cause Mahiru's apparition to appear and enshroud the blade and the arm wielding it with streaks of overwhelming flames, these flames are powerful enough to engulf an explosion in the midst of its vicinity, and even able to launch these flames at his opponent with one slash.
 * "Additionally, Guren can utilize the power of the demon weapon for other miscellaneous purpose such as filling areas like the classroom with its immense demonic auras. Within the power's vicinity and range, victims pass out unconscious on the floor if they don't have the strength or willpower enough to overcome it. However, if the targets have high psychic resistance, used wards, or are a potential candidate for the Black Demon Series, they're not any bit fazed by Mahiru-no-yo's demonic aura. Merely drawing the katana from its sheath alone seeps blackish gases made from within in and out of the blade."__STATICREDIRECT__