Secre Swallowtail

Nero is a woman sealed in the form of an anti-bird. She decides to stay alongside Asta after encountering him at the beginning of the Magic Knights Entrance Exam.

Appearance
As a human, Nero is a slender woman with dark-colored hair in a bob style. Two horns poke out of her hair on either side of her head, and two locks of hair stick up from the top of her head. She has dark bags under her eyes. She wears a dark-colored dress with thin straps and a short, ruffled skirt that looks like feathers.

As an anti-bird, Nero is a very small bird with a pair of sleek wings, a pair of tails that form an arrow at the tip and a black beak. One of her notable features is her slanted eyes that give Nero a hostile aura. Nero's feathers are black at the back, white at the front, and red on her face. In addition, Nero also possesses a pair of horns on either side her head and a pair of long black feathers sticking up from the top of her head.

Furthermore, the feathers around Nero's neck have a fuzzier texture then the rest of her feathers, which creates the sense of wearing a collar around her neck.

Personality
Nero is generally apathetic. When she becomes annoyed, she repeatedly pecks at Asta's head or pulls on his hair. Additionally, she also has a penchant to use this tactic to get her thoughts across to others as well, or when she is disagreeing with them.

In contrast to the way she treats him, Nero is very loyal to Asta, as she rarely leaves his side. She also constantly helps Asta in every predicament, such as guiding him through the dungeon or showing him the path to an artifact behind the wall.

Biography
Before the First Magic Emperor dies, Nero seals him in a statue atop the Demon God's skeleton on the outskirts of Hage. She then seals herself into the form of an anti-bird.

500 years later, Nero and a flock of anti-birds are present when the Magic Knights Entrance Exam is held. They pester several examinees prior to the start of the exam. After she encounters Asta, Nero decides to land on top of his head and sneaks into his clothes for a couple of days without revealing herself to the former.

After Asta's fight with Heath Grice ends, Nero decides to come out of Asta's clothes and takes off to observe the Sosshi village from above. She then locates the magic stone within the attic of the village church. Nero takes it to Asta and uses it to peck Asta's head in order to wake him up. Nero then tries to hold the item as tight as possible when Asta tries to take it from her with the intention to return it to the villagers.

Afterwards, Nero begins to chase Asta around the village while pecking his head, with Noelle Silva following them from behind. She then lands on top of Asta's head while the latter is giving a few words of encouragement to one of the children of the village.

Nero then follows Asta, Magna Swing, and Noelle back to the Black Bull base to report about the mission. During that time, Nero meets Vanessa Enoteca, who compliments the cute little creature. Later on, Nero follows Asta, Noelle, and Vanessa's venture to Kikka, where she remains in close proximity to Asta.

When Yami Sukehiro informs several Black Bull members about the emergence of a new dungeon, Nero sits on top of Asta's head while Noelle pets her. Subsequently, she joins Asta, Luck Voltia, and Noelle to the dungeon when they are assigned a mission to conquer it. On their way to the inner-side of the dungeon, Asta and Noelle start arguing on the name that they should use to address Nero. The argument heats up when the bird begins to peck Asta's head to show disagreement of his suggestion. However, Nero quickly agrees to Luck's suggestion.

After they walk in the dark for quite sometime, they finally arrive at the inner-side of the dungeon. During the time, Nero remains silent when Luck pulls a prank on Asta and Noelle and leaves almost immediately and when a trap is activated and Yuno saves Asta and Noelle from it.

Nero continues to remain silent while Asta and Noelle have a conversation with the Golden Dawns Klaus Lunettes, Yuno, and Mimosa Vermillion. Later on, after both teams go their separate ways, Asta and Noelle continue to explore the dungeon. Nero finally breaks her silence by showing them a path after she sees that both Black Bulls do not know which direction they need to go. Asta and Noelle are still unable to reach their destination as they are lost in an area with an unusual gravitational field. When Asta tries to ask Nero about it, the bird decides to ignore him and returns to being silent while watching both of them.

After a while, Nero, Asta, and Noelle finally find the correct path and cruise through it towards the center of the dungeon until Asta decides to take a detour to save Luck. While the Black Bulls fight against Lotus Whomalt of the Diamond Kingdom, Nero lands on top of Asta's head, but quickly flies away to avoid being a hindrance to them. After Lotus is defeated and manages to escape, Nero follows the Black Bulls to the center of the dungeon. When she arrives along with Noelle and Luck, Nero sees that Asta and Yuno are prepared to fight against another Diamond Kingdom's mage, Mars.

After Asta manages to render Mars unconscious, Nero returns to Asta and lands on top of his head. Not long after they enter the dungeon's treasury, Nero quickly tugs Asta towards a wall that has the same locking mechanism as the door to the treasury. She then immediately starts pecking Asta on his head when the boy does not understand the hint.

Suddenly, Mars breaks through the treasury's door and manages to incapacitate everyone except Asta and Mimosa. Mars then sends Asta crashing through the wall that Nero showed to Asta earlier. Seeing that Asta is inside the hidden room, Nero quickly follows and flies over him before landing on the pommel of a sword covered with dirt. After Asta is finally able to understand Nero's hint, the boy takes the sword and resumes his fight.

After Mars is instantaneously defeated by Yuno, Nero remains close to the fainted Asta as all of them rush towards the exit as the dungeon is collapsing. The anti-bird immediately lands on top of Asta's head, the moment the boy awakes and Klaus suddenly hugs him.

A week after the mission, at the Black Bull's headquarters, Nero joins Asta on a feast that is given to the latter for his performance during the mission. She also remains close when Asta and Noelle need to go to the Magic Knights headquarters in the Noble Region to report about the mission. Nero remains silent and does not bother Asta in anyway while the latter is in audience with the 28th Magic Emperor, Julius Novachrono, nor when he is attending the ceremony and banquet that honors several members of the Magic Knights.

However, when Asta begins to get annoyed while his comrades are being humiliated by those honorary Knights, Nero decides to take off from Asta's head as she watches the latter confronting them. After the commotion dies down when someone enters the banquet hall to inform the Knights that the Royal Capital has been invaded, Nero returns to Asta's side as the latter joins the Knights' discussion regarding their counterattack strategy. Not long after, the anti-bird follows Asta when the latter decides to move out before the others. Nero remains by Asta's side until they find the man behind the invasion, Rades Spirito.

While Asta is fighting against Rades, Nero stays on top of a little girl's head that Asta saved from the terrorist. Nero remains unruffled even when the little girl is about to be attacked and Noelle steps in to protect her in Asta's place. Afterwards, Nero stays put on top of the little girl's head while they are observing the fight from afar. When Asta returns with the Magic Emperor after being captured by members of the Eye of the Midnight Sun, Nero immediately leaves the little girl's head and greets Asta by pecking his head.

Later on, Nero stays on top of Asta's head as the Black Bull members prepare their departure from the Royal Capital. The anti-bird also remains composed when Yuno sends his farewell to Asta by launching an attack towards him. As they arrive at the Black Bull's headquarters, Nero keeps herself comfortable on top of Asta's head while the Black Bull members are having a conversation around him.

During a blind date, which Asta attends alongside Luck and Finral Roulacase, Nero remains in silence as she observes from the top of Asta's head. However, when Nero notices Sekke Bronzazza is also on a blind date, the anti-bird quickly takes off to the latter's table and intensely observes him. Nero then shifts her attention and observes Asta, alongside Noelle, when the boy is taken into an alley by his date, Rebecca Scarlet. At the end, Nero returns to Asta's head as the latter asks Rebecca the purpose of a blind date.

Nero then stays by Asta's side when the latter visits Rebecca in Nairn. The anti-bird flies away when Gauche Adlai assaults Asta. After returning to Asta's head, Nero then discovers Noelle who is watching them from afar. She approaches the noblewoman and stares at her as Noelle learns about Asta's decision to stay at Rebecca's house. After dinner, Nero goes to sleep next to Asta in one of the bedrooms. However, the moment Gauche sneaks into the bedroom and causes some havoc, Nero quickly flies outside from the hole, which the mirror mage made. When they realize that the children of Nairn have gone missing, Asta and Gauche, along with Sister Theresa from the church, set forth to pursue them. However, Nero decides to stay at the town alongside Noelle and Rebecca.

Back in the house, Nero sits on Pem's head while Noelle reports to the Magic Knights. Nero settles on the window sill, staring out and waiting. Nero reunites with Asta after he returns from meeting with the Magic Emperor. She then sits on his head when he returns to Nairn. Marco returns Asta's squad robe and Rebecca kisses Asta's cheek.

Nero accompanies the Black Bulls on a party on Raque's beach. She settles in a nest next to Vanessa's chair. A week later, Nero secretly follows the Black Bulls into the Seabed Temple. She locates the magic stone and brings to the Black Bulls after Temple Battle Royale. She returns to sitting on Asta's head when they all leave the temple and return to the base.

She sits quietly as Asta travels to the Royal Capital to report to Julius. The meeting is interrupted by a report that the Diamond Kingdom is attacking Kiten. The Black Bulls travel to Kiten and Nero stays near Asta who tries to direct the citizens to safety. However, she stays behind when Asta launches himself at Yagos.

Nero accompanies Asta on his visit to Owen. She stays with him during the celebratory feast. Later, Asta goes off to contemplate his diagnosis and Nero sits next to him on the rock. The next morning, she is back to sitting on his head and shoulder while he wanders the base.

Nero follows Asta to the Witches' Forest. After all of the fighting is over, Nero lands on the Witch Queen's shoulder and pecks her magic stone earring. When the Black Bulls return to the queen's throne room, Nero sits on Asta's head while the queen hands over the stone and tells them about the Elf Tribe. She remains on Asta's head while the Black Bulls bid farewell to their new friends, return to their base, and greet the other returning Black Bulls.

During the Star Awards Festival, Nero sits on Asta's head. When the Black Bulls are ranked second, Nero flies off of Asta's head before Yami throws the boy on stage.

A week later, Nero accompanies Charmy Pappitson to the Royal Knights Selection Exam. She hides the two of them in a ball of cotton within Noelle's hood. Nero silently watches the matches from atop Charmy's head.

Several days after the exam, Nero hides in Asta's clothes before the boy is taken away by Mereoleona. Nero pops out when Licht confronts Asta and Yuno. The bird pecks at Asta's forehead but flies away to avoid Licht's attacks. She sits on Mimosa's head and watches the fight. When Licht blasts the humans out of the dungeon, Yuno protects Nero and Mimosa as they all fall down into the water below. Nero remains on Mimosa's head while the remaining Royal Knights regroup on the lake shore and decide to return and defend the kingdom.

The bird follows Asta and Yuno when the two leave to defend Hage from attack. She watches the fight from the church's steeple and flies down after Asta exorcises the elf spirit. She then settles on Asta's head and travels with the boy to a town in the Common Region. She watches the fight from afar and, after Lufulu is exorcised, flies down to settle on Asta's head again. She remains on Asta's head while the Black Bulls return to their base and they travel to Hecairo. She remains in the base when Asta is fired from a cannon.

After Drowa is exorcised, Nero flies over and sits on Gauche's head. She stays on Gauche's head when the Black Bulls remain behind to fight a group of possessed Golden Dawns. Nero reacts to Yuno's magic stone opening a gate to the Shadow Palace. The bird follows Yuno and Charmy but the gate closes before she can enter.

Nero flies over to the destroyed throne room of Clover Castle where Finral has finished recovering. Nero pecks at the Black Bull's forehead and then asks to be taken to the Demon God's skeleton. After Finral teleports them there, Nero has him take the magic stones from the tablet and place them in the First Magic Emperor's statue. This breaks the seals on Nero and the statue. Nero returns to her human form and welcomes back her prince. She coldly stares back when Finral tries to hit on her. She then grabs the prince's hand and Finral's hand so the prince can launch them all back to the castle. Along the way, Nero reopens the gate into the Shadow Palace and drops Finral in the throne room.

Magic

 * Sealing Magic: Nero uses this form of magic to place magic seals on people.

Abilities

 * Mana Sensory: Nero possesses the ability to sense mana within living creatures and inanimate objects. Additionally, her abilities allows her to locate magic items from a long distance and through walls. She also could use it to determine the quickest path towards the mana that she is sensing.


 * Immense Magic Power: Nero was stated by Finral to have magic power that is even greater than that of the elves.

Trivia

 * Asta wishes to name her "Toritarou" (トリタロウ) while Noelle wishes to name her "Sylvants Schnauzer" (シルヴァンタス シュナウザー) before agreeing on Luck's suggestion, Nero, which means "black" in Italian.
 * Her name may be a reference to the Roman emperor Nerō Claudius Caesar Augustus Germanicus.
 * Nero ranked fifth in the first popularity poll and nineteenth in the second.
 * Nero's favorite thing is the tops of people's heads (the softer, the better).

Navigation
Nero Nero