Nero (ネロ Nero) is the Relic Eater contracted Kyouya Kirigaya and is designated as Malleus Malificarum V. Her intrinsic abilities pertain to the use of a wide variety of poisons both in and out of combat.
In her human form, Nero wears a shoulder-less dark green dress and matching leggings. She has long, shoulder-length hair and wears a small crown while also having a lock similar to Lapis' around her neck. Most commonly however, she takes on the appearance and voice of Kyouya's childhood friend, Yoshimizu.
In Witch Hunter armor, Nero's armor is described in a similar vein to Lapis's armor, only instead of the "azure colored knight', Nero's armor is described as a "green demon" with a malformed gun barrel on the right hand as its primary weapon. The armor itself is described as being "alive" and "pulsating" with its strength coming from poisoning the user's own body whereupon its effects are immediately visible in their protruding blood vessels.
Nero's vibrant personality can be described as being similar to her abilities as her goading words and intentionally aggravating tone are venomous to her master. Like other Relic Eaters, Nero seeks an attribute from her wielder and her chosen attribute is revenge. Because of this, she must goad and evoke Kyouya's anguish and torment and breed it into anger and vengeance for her to be in top condition. For this reason alone, she continues to mock and remind him of his shortcomings that had his squadmates killed and walk around in the guise of his dead friend. Outside however, she still seems to be subservient to her master and while not hostile, she was still prone to pick fights and argue with others.
Two Alchemists Arc Edit
Nero was gifted from Sougetsu to Kyouya after the events of the alchemist conflict when the latter declared he was willing to do anything to bring Yoshimizu back.
Festival of Fools Arc Edit
Kyouya utilized Nero to hunt down Reima after Mephisto's defeat, with the former trying to reach his father to try and clear his name. Reima was soon cornered and begged for his life while Kyouya pulled Nero's trigger and killed Reima without hesitation.
Hyakki Yakou Arc Edit
Kyouya and Nero appeared in front of Kiseki and Takeru in a busy street where Kyouya attempted to capture her. Takeru noticed someone similar to Yoshimizu beside him and began hearing her voice as she introduced herself as Nero, even with the intention of killing them. The fight is broken up with the Dullahans' arrival and Kyouya and Nero retreat and join them in protecting the convoy with Kiseki's containment cell. Nero was called upon when Kyouya and Kurogane confronted 3 enemy Einherjars. Soon, Kyouya drives the truck alone before deciding to kill Kiseki instead and is quickly confronted by Takeru and the two begin their fight again. Kyouya's overexertion however has his advantage become meaningless as he begins to weaken, even if Takeru wasn't able to land a single hit one him once during their fight. It is revealed that Nero's healing ability on Kyouya is compromised as he instead gave the healing poison's effects to Yoshimizu. Nero is forcibly disarmed from him as he is shot by Ouka's Vlad and he falls unconscious.
Crimson Lotus Arc Edit
After Kyouya excuses himself from the 35th Platoon's campfire, Ouka's words begin to bother him. Sensing doubt in her master's heart, Nero shows herself, imitating the face and voice of Yoshimizu to actively provoke him. Nero dances around her master and reminds him that without his constant desire for vengeance, she will not be able to utilize her poison to maintain Yoshimizu's health. Kyouya strikes at her in anger but she disappears, laughing all the while. Kyouya continues to utilize her and opens up a path to Laugh Maker for Ouka to fulfill her own revenge.
Heretic Alliance Arc Edit
With Yoshimizu's body transferred to the First Laboratory for treatment, Kyouya and Nero acted as her sole guards while the Alchemists were more concerned with researching Kiseki, who was also contained there. Nero was called upon when Kiseki was awakened and Kyouya eventually came to clash with Takeru where Kyouya ultimately lost but was eventually able to save Yoshimizu through the transfer charm Kiseki had denied Takeru from using.
Witch Hunt War Arc Edit
Nero is seen wheeling Yoshimizu around the Heretic Alliance headquarters where she briefly argues with Lapis before assuring Takeru that she is not here to fight. Yoshimizu asks for Nero to calm herself and she disappears from the conversation with Lapis doing the same. Kyouya makes "amends" with Takeru and he joins the 35th platoon in retrieving a document that held crucial information regarding Sougetsu. Kyouya and Nero held off the Guillotines closing in on the building and later joined Takeru in their struggle against Kurogane. Later, as the war escalated, Kyouya once again held off enemy forces while the 35th platoon confronted Mother Goose and Orochi. Before he engaged the enemy, Kyouya asked Nero why she bothered to stay obedient to him when the terms of their contract was already fulfilled. Nero simply responds that she has no choice in the matter and wouldn't really care if Kyouya were to die as she should simply find someone else to contract with. However, Nero comes to admit that Kyouya's vengeance was the most satisfying one to fulfill, much to his entertainment.
Call of Twilight Arc Edit
Kyouya and Nero finish a contingent of Einherjars before the former heads out to regroup with the alliance, only to be distracted in defending a local shelter from Kiseki's spawns. Nero complains why Kyouya is acting out like this but he demands for her to stay quiet. The duo are quickly joined by Sage and Yuzuho who follow through with protecting the shelter and Kyouya decides to utilize Nero's wide, area of effect intrinsic magic to halt the advance of Kiseki's spawn. An area of effect magic is invoked and the flesh mass and the spawns are slowed down by a growth of poisonous mold that begins to cover them. She is present during Kurogane's return after the trio become exhausted in defending their position.
Promise of Dawn Arc Edit
Nero is finally sated after Kyouya encounters Haunted after the latter's duel with Kurogane. With Haunted exhausted and busy gloating over his apparent victory over Kurogane, Kyouya is able to approach him without Haunted noticing and Kurogane gets clear as Kyouya uses Nero's full strength to unleash a vengeful storm of bullets that Haunted is unable to defend against. Haunted is reduced to a dismembered head and Kyouya finishes him off with a clean shot to his head.
With the aftermath of the war, Nero's contract with Kyouya was terminated in good terms and she was separated from him after the latter retired from the Inquisition's service. Nero has yet to contract with a new master and physically remained in the archives to be contracted with a prospective master but none have yet to appear to match her specifications. She frequently appeared before Kyouya and Yoshimizu in the bakery the two now run.
Relic Eater- Malleus Malifcarum V: Nero is classified as a shotgun type Relic Eater whose destructive abilities she can unleash upon her wielder's enemies could also rival the damage she does to her own user with her poisonous effects. Like other Relic Eaters, Nero demands something back from her user and she asked for anger and the desire for revenge, something Kyouya had an abundance of.
Intrinsic Magic- Poison: Nero's intrinsic ability is notably one of the only non-ancient attribute ability used among Relic Eaters. Her power allows her to create a powerful mixture of multiple poisons across the attribute's spectrum that is primarily utilized to remove mana from enemy witches after application. However, her poison is more often used by Kyouya by using it on himself to increase his strength and heighten his reflexes. This came with the adverse effects of inflicting crippling damage to the user as the poison strains and forces the body to bear with its effects but the benefits were substantial. The poison could also be modified to become an advanced healing strain of poison that is said to have one of the highest healing capabilities among Relic Eaters.
- Babylon: An intrinsic magic spell that disperses a poisonous mist from Nero's barrel and clouds an area in fog. A magic circle is cast and shattered where its pieces pierce though its targets countless times within the cloud, infecting them with an amalgamation of afflictions taking the shape of rapidly spreading molds across the targeted bodies.
Witch Hunter Armor: The armor Nero grants her user takes the shape of a dark green armor that is described to appear "demonic" and this is further emphasized when the user is utilizing her poison's effects on their bodies, causing the armor to pulsate and look organic. The primary weapon is a large cannon that is merged to the armor's right arm.
Flexible Material: Nero's other offensive capabilities are through the arm cannon that shoots off magic-enhanced shells. The cannon however can be made to change shape and be used in conjuction with different types of ammunition to fight against any threat.
- Long Barrel: An extended barrel that allows for greater range, primarily used along with frag grenades.
- Sawed Off: An extremely shortened barrel length for when the target reaches the minimum distance from where Nero can be fired. Primarily used in conjunction with buckshots.
- Triple Thread: Nero's single muzzle splits into three-interconnected muzzles where the armor also entrenches its feet into the ground, taking form of a mounted gun emplacement. Allows for rapid-fire capabilities to unleash a hailstorm of bullets.
- Thousand Thread: A form that presumably can only be used when the user reaches their peak in anger and vengeance. Nero's muzzle is split into thousands of independent barrels allowing for simultaneous rapid-fire over a large area.
- Tonfas: Nero's melee form that can be utilized as dual tonfas for close quarters combat. The tips of the weapons retain their firearm capabilities.
- Buckshot: Nero's gunfire is made to spread over a wide area with an enormous amount of bullets fired off, more effective at close range before the bullets disperse.
- Slug: A condensed, single shot gunfire that acts similarly as a grenade but is more compact with its explosion.
- Frag: High-explosive grenades that are launched over a fair distance. Their explosions cover a much larger area.
- Following the trend of Relic Eater namesakes, Nero is named after the 5th and last Roman Emperor of the Julio-Claudian dynasty. Nero is similar to his cousin Caligula in a sense that both their rule involved their descent into madness. Nero's reign was controversial enough to have him branded as a public enemy whereupon he committed suicide.