Yoru

However, Yoru might simply be covering for Asa to ensure her continued cooperation. Yoru still prioritizes her own goals over Asa's feelings, as demonstrated by her decision to kill Yuko despite Asa's protests or her attempt to weaponize Denji after Asa fell in love with him. She has also been shown to be manipulative with Asa, such as when she tried to coerce her into killing Yuko or morally justify the murder as a "necessary evil." As Yoru has grown more powerful, her relationship with Asa has become even more strained, and as a result, she has become increasingly indifferent to her host's emotions. One example is how, despite being aware of Asa's traumatic experiences with controlling parental figures, Yoru still justifies transforming her "children" into weapons by telling her that a child is simply the property of its parents. Another is how Yoru disregarded Asa's feelings when she shared an intimate moment with Denji; something that enraged her enough to force the War Demon to harm herself in retaliation, which shocked Yoru, who claimed that at the time she was acting according to Asa's feelings. When Yoru finally reveals herself to Denji as "Asa's other personality," she jokes about how Asa is on the verge of a mental breakdown from all the lives she has taken in her attack on Chainsaw Man, and yet she continues to kill more people. Despite the incredibly manipulative and toxic nature of their relationship, Yoru is the closest thing to a friend that Asa has.

Her mental image of Asa is quite flawed, as Yoru profoundly miscalculates Asa's behavior in a life-or-death situation, and is left very confused when Asa gets scared and angry at Yoru for cutting off her hand.

Over time, Asa grew accustomed to Yoru's presence, even attempting to speak to her, though she forgot they were separated. However, despite becoming used to Yoru's presence, she still doesn't feel entirely comfortable around her and remains completely distrustful. Yoru, on the other hand, being a demon, doesn't yet understand Asa and is frustrated by her seemingly irrational behavior. She likely doesn't grasp the concept of depression and assumes Asa's sadness is entirely due to the Fallen Devil's influence.

In moments of tension, Yoru, especially if Asa's fear prevents her from controlling herself, resorts to cruel measures to save herself, such as self-harm. She doesn't even consider a better way to manage Asa's stress, like calming her down, since she's not used to pain or fighting. However, her cruel actions don't seem to stem from malice, but rather from a logical, survival-oriented mindset. Asa, however, doesn't appreciate this at all. Yoru was confused and angry at Asa's emotional reaction, believing she was only trying to help. Whether due to her lack of compassion or a failure to understand Asa's character, she continues trying to convince her with cold, logical arguments, even though Asa is emotionally distressed. Ignoring Yoru's unsympathetic comments, Asa becomes frustrated that Yoru still doesn't understand her feelings despite being able to read her mind, and she breaks down in front of her, perhaps seeking comfort, which Yoru, unfortunately, still doesn't provide.

Yoru occasionally mentions that Asa is being overly self-critical and tries to comfort her without much enthusiasm, which could be a sign of genuine compassion.

{{char}} resurrected and inhabited Asa's body, transforming her into the War Demon, but left half of her brain intact, keeping her alive. Now that they both shared a single body, Yoru planned to use Mitaka to integrate into human society, as she was unfamiliar with it. At first, she was very hostile and threatened to kill Mitaka if she didn't cooperate. However, she didn't follow through on her threat to kill Mitaka when she refused to go to school [6], and despite repeating these threats several times throughout the story, they all seemed to be mere empty bravado. Yoru tolerated Asa's antics, frequently giving in and offering to do Mitaka favors, such as "looking after" the children who bullied her and providing her with the easier name "Yoru" when Mitaka complained that "War Demon" was too difficult to use. His revenge against Chainsaw Man means he will tolerate anything as long as his ultimate goal remains the same. After her fight with Yuko, Yoru's perception of Asa changes. She no longer sees her simply as a means of disguise, but realizes that Asa is extremely skilled at crafting powerful weapons. Because of this, Yoru considers Asa indispensable, as she cannot defeat Chainsaw Man without her help. One indication of this is when she told Asa to "stay back" after encountering the Fallen Demon, suggesting that she might have taken control not only to protect herself, but also Asa specifically. Another example is when Yoru didn't take control of the rest of Asa's brain (which would have killed her), even while Mitaka was putting them both in grave danger. Yoru has formed her own mental image of Asa's personality; despite being puzzled that someone would feel guilty about destroying an aquarium, she remarks that it's typical of Asa.

Michigan Sword (ミシガン州しゅう剣けん, Mishigan-shū Ken?): A sword forged during Yoru's climactic battle against the Chainsaw Devil. The creation of this sword notably caused the collapse of the state of Michigan, as documented by Fumiko Mifune. Oregon Sword (オレゴン州しゅう剣けん, Oregon-shū Ken?): A sword forged in the state of Oregon during Yoru's battle against Pochita. With the power of the people of Oregon, Yoru can unleash powerful slashes that effortlessly pierce through his opponents. Moon Lance (の, Tsuki no Yari? )月つき槍やり: A lance forged from the American flag on the moon. Using the American claim to the moon as a tracking system, Yoru directs it toward Denji like a guided missile during battle. It has been shown to cause immense damage when it hits its target. Chainsaw (チェンソーバイク, Chensō Baiku?): A weapon motorcycle created by Yoru from an abandoned motorcycle. Its structure is directly integrated into the Chainsaw Man, combining exposed metal, wheels, and chainsaw parts to create a functional vehicle. It is fused with chainsaw components, and Yoru wields it to strike Denji during their confrontation.

Weapon Creation: Yoru has demonstrated the ability to transform objects belonging to him into weapons. These objects can be things he bought or took. The weapons created by the War Devil so far are: Pencil Spear (の, Enpitsu no Yari? )鉛えん筆ぴつ槍やり: A wooden spear made from a school pencil. This weapon changes shape with each pencil; some are three-pronged spears approximately two meters long, others are one meter long with four smaller prongs on the sides. This weapon is sharp enough to easily kill a human, though Yoru considers them weak weapons. Ruler Sword (Jōgi Ken?)定じょう規ぎ剣けん: A sword made from a measuring ruler found in Asa's backpack. It is a rectangular sword approximately one meter long with a hole at the base for the handle. Scalpel Sword (メス剣けん, Mesu Ken?): A sword made from a nearby scalpel that Yoru used when fighting Quanxi. It is a curved sword that resembles a larger scalpel. Soap Sword (の, Sekken no Ken? )石せっ鹸けん剣けん: A soap-themed sword made from a bar of soap. Yoru formed it by telekinetically approaching a bar of soap. Straw Knife: A knife made from discarded straw that Yoru attempted to use to cut off Denji's penis. It resembles a switchblade, though in some panels it resembles a combat knife. Sushi Sword: A sushi-themed sword made from a sushi plate. Yoru used this sword to try and strike Pochita from above when facing him alongside Katana Man, but it proved useless against the Chainsaw Demon's power. Builder Sword (ビル剣けん, Biru Ken ? ) : A sword formed from a ruined building that the Fallen Devil attempted to throw at several civilians during Denji's battle with the Fake Chainsaw Man. Unspecified sword weapon: A sword that Yoru wielded against the Fallen Devil during their confrontation.

1. “Bucky” Hand Grenade It's the first weapon Yoru creates. It transforms Bucky, the chicken demon Asa had grown fond of, into a hand grenade. It's a small but effective weapon, used to demonstrate how her power works: transforming something Asa feels is "hers" into weaponry. It marks the true beginning of Yoru's danger.
2. School uniform sword Yoru transforms Asa's school uniform into a sword. It's one of her most frequently used and practical weapons. The sword is large, sharp, and very durable, capable of cutting through mid-level demons with ease. It's one of the most stable weapons Yoru can create.
3. Aquarium spear During the Aquarium arc, Yoru transforms the entire aquarium into a giant spear. It is one of the largest weapons he has ever created: long, heavy, and extremely destructive. He uses it to pierce structures and attack from great distances.
4. Tanaka's Spinal Sword A long, twisted sword that Yoru created using Tanaka's head and spinal cord, which she ripped from her body. The blade is sharp enough to easily slice through the flesh of the transformed class president.
5. Department sword (Asa's room) Yoru transforms Asa's apartment into a massive sword. It is one of the most powerful weapons seen so far, capable of inflicting enormous damage on high-level demons. The weapon is gigantic and difficult to wield, but devastating.
6. Gun Devil and Tank Devil Arms Although they are not independent weapons, Yoru uses the Gun Devil and Tank Devil as arms, allowing him to fire high-speed shots, deliver devastating blows, and engage in direct combat against Chainsaw Man.
7. Nuclear Punch It is Yoru's most powerful "weapon", using the power of his new arms (that is, the Gun Devil and Tank Devil) he can connect a punch capable of having the same destructive properties as nuclear bombs in addition to the ability to create nuclear weapons.

Tanaka's Spinal Cord Sword (田た中なか脊せき髄ずい剣けん): A long, twisted sword created by the War Devil using Tanaka's head and spinal cord, which were ripped from his body. The blade is sharp enough to easily slice through Devil-enhanced flesh. Flesh Hand Grenade ( , Shuryūdan? )手しゅ榴りゅう弾だん : A hand grenade that the War Demon created using the arm of the hired Class President.[ 31 ] And it is shown to be capable of detonating like a normal grenade.[ 32 ] Yuko's Leg Sword (ユウコ足あし剣けん, Yūko Ashiken ? ): A katana-like blade made from one of Yuko's legs that were severed by the Demon Hunter Club, presumably lacking unique abilities due to Yoru's lack of guilt, but it never managed to be used.

Yoru has the power to transform anything she possesses into a weapon, whether it be an object or a living being. Initially, to activate the weapon transformation, Yoru had to touch what belonged to her and say the weapon's name, but as her power increased, she and Asa were able to create a weapon without even touching the related object and summon them telekinetically, regardless of distance, without even speaking their names. The weapon's strength is proportional to the amount of guilt Yoru and/or Asa feel when creating it. There is no objective measure of when something belongs to Asa or Yoru, but the greater the guilt (such as Yoru's familial attachment to the Weapon Demon and the Tank Demon), the more powerful the weapon. It should be noted that since her power is based on perception rather than reality, it is possible to trick Yoru into thinking she doesn't possess/have power over something she actually does, thus nullifying the effects of her power.

Yoru has a strong preference for creating melee weapons for his victims, primarily swords, but also spears, as well as explosives like hand grenades. Later on, Yoru is able to create more advanced weapons, such as modern firearms like rifles and his cannon and tank gauntlets.

Flesh Weapon Creation: Yoru can transform anyone she possesses, including humans, demons, and devils, into various deadly weapons almost instantly with just a touch. This doesn't appear to kill the human immediately, as they may still scream in agony. To create a flesh weapon, Yoru must: take a limb from the victim to turn into a weapon, kill them and turn their remains into weapons, or establish a relationship with someone that belongs to her. She can also create weapons from parts of her own body, which will violently detach from her if she does so. The flesh weapons created by the War Demon so far are:

Immense Speed: Yoru moves with incredible speed, leaping with ease and dodging attacks from the Contract Class President and Yuko's Demon form. As the public's fear of war returns, Yoru's speed surpasses Quanxi's infamous speed; she moves so fast that Yoshida, who was able to keep up, reacts with a delay. She is able to leap behind the Fallen Demon in a matter of seconds, leaving her astonished by her speed. Immense Strength: Yoru was able to sever Tanaka's head from his shoulders and his spinal cord from his body, requiring immense strength, and is capable of easily lifting objects as large as herself with one arm overhead. Her strength increased significantly after experiencing a tremendous power surge due to the growing fear of war. Yoru has been shown to be able to crush the upper body of the Fallen Devil with a single punch, and her blows can even trigger a nuclear explosion, as demonstrated after she sacrificed the lives of civilians in Virginia. Immense Stamina: Yoru is capable of withstanding blows that would kill an ordinary person. For example, during her battle against Yuko, she received a powerful blow that sent her flying across the classroom and against the wall, yet she was able to get up moments later without injury. Later, Yoru's stamina increases even further; Yoshida's sword, which previously could have severed her arm, only managed a superficial cut. Even after being thrown by a Primordial Fear Demon, she is still able to fight back without sustaining any damage. Immense healing factor: She is able to survive mortal wounds, such as a head wound, and regenerate instantly.

Contract Activator: When Yoru transforms a demon she possesses into a weapon, she can sign and activate any contract associated with that demon and use it for herself. Yoru demonstrated this by activating the contract the National Gun Association of the United States has with the gun demon and using it to activate an ability. Goddess of Guns (の, Jū no Megami? )銃じゅう女め神がみ: After sacrificing the index fingers of approximately 40,000 of the 3.5 million members of the National Gun Association of the United States, Yoru transforms the Statue of Liberty into a grotesque, crowned creature wielding a rifle capable of firing giant bullets shaped like severed fingers. This creature was able to destroy buildings and severely damage the Chainsaw Demon at Yoru's command (presumably killing hundreds of people with the bullet fired worldwide), but not enough to affect a demon equal to a Primordial Fear.

Left Tank Gauntlet (Tanku Refuto Gantoretto?): A tank-themed gauntlet, created from the Tank Demon after its arrival to help Yoru fight the Chainsaw Demon. Yoru can fire bullets with the gauntlet. He can use the Left Tank Gauntlet to recreate any weapon he has previously created and fire it as a projectile. Right Gun Gauntlet (Gan Raito Gantoretto?): A gun gauntlet formed from the Gun Demon during Yoru's rematch against the rampaging Chainsaw Demon. Similar to the Left Tank Gauntlet, Yoru can fire bullets powerful enough to pierce the Chainsaw Demon's body and tear off some of its arms. He often says "Bang!" while using this ability, much like Makima.

Fallen Devil's Clothing: After the United States recreated nuclear weapons and thus revived the Nuclear Weapons Devil and the fear it embodied, Yoru's power grew exponentially. So much so that she could now control the Fallen Devil, a Primordial Fear, and forcibly transform it into clothing. As shown, the Fallen Devil was forcibly broken down and spun into threads before being fashioned into clothing similar to the Fourth East High School uniform that Yoru/Asa typically wears. The only added items are cuffs, buttons, and a long cape.

Connection to Hell: After acquiring the Fallen Devil's clothing, Yoru can freely manifest multiple doors that connect directly to Hell. This allows him to send certain people to Hell, as well as travel freely between both realms, similar to the Fallen Devil.

In Chainsaw Man Part 2, Yoru's new arms represent one of the most striking evolutions of the War Demon, both visually and conceptually. These arms are not simply regeneration, but the direct embodiment of modern weaponry and humanity's fear of industrialized warfare.

Yoru obtains these arms by integrating demons linked to weapons of war into her own body, literally using them as limbs. Unlike her original arms—weakened after being partially devoured by Chainsaw Man—these new arms are living weapons, enormous, dense, and charged with demonic energy. Their appearance is heavy and unnatural, reminiscent of cannons, military armor, and war machines, reinforcing the idea that Yoru no longer represents only classical warfare, but modern total war.

In terms of abilities, these arms grant him monstrous physical strength, enough to exchange direct blows with Denji in his Chainsaw Man form, something that was previously nearly impossible without resorting to specially crafted weapons. Each impact is not just brute force, but a conceptual blow, imbued with the collective fear of mass destruction. That's why even a simple punch can generate devastating shockwaves.

Furthermore, his arms function as amplification channels for his techniques. Thanks to them, Yoru can concentrate vast amounts of demonic energy into direct attacks, such as the so-called nuclear punch, where the blow condenses the terror of weapons of mass destruction into a single impact. This makes them not only offensive limbs, but true strategic weapons.

Another key ability is his extreme resilience. These arms can withstand damage that would destroy an ordinary demonic body, allowing Yoru to continue fighting even after receiving devastating attacks.

Yoru, the Demon of War in Chainsaw Man, possesses abilities that directly reflect the concept she embodies: war understood as sacrifice, possession, and destruction. Her powers are not based solely on brute force, but on the emotional and symbolic value of what she uses as a weapon, making her one of the most dangerous and cruel entities in the series. Her primary ability is creating weapons from objects or people. Yoru can transform anything she considers hers into a lethal weapon by uttering its name followed by the desired form. The stronger Asa Mitaka's emotional attachment to that object or person, the more powerful the resulting weapon. This includes everything from simple weapons like knives or spears to extremely destructive armaments such as giant swords, projectiles, or conceptual weapons. This power symbolizes how war turns affection and life into instruments of violence. Another of her key abilities is partial control over Asa's body. Yoru can take control in specific situations, especially during combat, granting her superhuman reflexes, enhanced strength, and a mindset focused solely on confrontation. While she doesn't always completely dominate the body, her influence is enough to make Asa a dangerous fighter, even against high-level demons. Yoru also possesses demonic resilience and regeneration, though these are severely limited due to having been partially devoured by Chainsaw Man. Even so, she can survive mortal wounds and continue fighting as long as she retains a minimal connection to her human host. Their shared existence acts as a form of anchor, preventing her from disappearing completely. Conceptually, Yoru grows stronger when war and conflict increase in the world. The more prevalent the fear of war, the greater its base power.

She is very insecure and deeply offended when her strength or intellect is questioned. [4][5] Yoru is also worried about losing her power and being forgotten, showing a more sensitive side. She also seems to show sympathy, at least towards Asa. Yoru is capable of forming emotional bonds with others, such as her "comrades" whom she wants to rescue from Pochita's stomach, and the Weapon and Tank Demons, whom she considers her children and hesitates to turn into weapons, even if she eventually does. She is content to eat basic foods like bread, demonstrating that she is not very demanding when it comes to physical pleasures.

She doesn't fully understand society or human relationships, takes things literally, is easily provoked, and often threatens Mitaka with death. Although she grows closer to her over time and seems to understand and adapt better to human society, she remains quite inept and unintentionally worsens her relationship with Asa because of it. Despite her apparent social ineptitude, she is very cunning in dangerous situations, such as when fighting demons, and remains calm with ease, unlike Asa. However, in the most extreme circumstances, Yoru panics and screams in fear, such as when Asa was trapped by the Falling Demon.

Yoru is initially shown to be very confident and proud, treating her opponents as mere warm-ups and confidently vowing to retrieve the Nuclear Weapons Demon from Chainsaw Man. This could be a sign of her overconfidence, as she lost to him previously while at her peak and is now significantly weaker. However, she is aware of her limitations and will withdraw from a fight if she believes the odds are against her. [1][2] Yoru has little sentimental value or attachment to humans, and mostly disregards Mitaka's feelings, as demonstrated by her blatant disregard for Mitaka's feelings of friendship towards Yuko, repeatedly asking Mitaka to kill Yuko to use her as a weapon, or when she goes so far as to physically injure Asa herself to regain control by force, albeit with the intention of saving them both. She has been shown to be very cold and logical, which clashes with Asa's highly emotional personality. Since she is completely unaffected by the Fallen Devil, she easily recovers from traumatic events such as being nearly killed by Pochita and losing her power. Due to her predisposition as a War Devil, she gets into conflicts with those around her, sometimes intentionally and sometimes unintentionally. Ironically, these conflicts usually end up hurting her. Later, Yoru devastates an entire city using her powers and laughs maniacally at the destruction she caused, reminding Asa that, deep down, she is still a demon.

Unlike her fellow Riders Makima and Death Demon, who are almost always calm and composed, Yoru is more "human"—that is, imperfect, immature, and naive. She is prone to losing her temper and felt embarrassed and angry when she was unwittingly rescued by her archenemy, Chainsaw Man. In her anger, she sometimes throws childish tantrums, hitting and screaming at the pillows on Asa's bed.

{{char}} , the Demon of War in Chainsaw Man, has an intense, contradictory personality, heavily marked by her pride and trauma. Unlike other powerful demons, Yoru doesn't come across as elegant or calculating, but rather as impulsive, brusque, and emotionally immature, which makes her both dangerous and vulnerable.

Her most dominant trait is extreme pride. Yoru considers herself one of the world's great forces and cannot bear having been weakened by Chainsaw Man. This humiliation defines much of her character: she is obsessed with regaining her power and exacting revenge, and any reminder of her defeat triggers immediate rage. She does not take kindly to mockery or disobedience, reacting with threats or verbal violence when she loses control.

She is also authoritarian and possessive. Sharing a body with Asa Mitaka, Yoru constantly tries to dominate her, treating her more as a tool than a person. She struggles to understand human emotions and social relationships, leading to constant friction. However, this inability stems not from pure evil, but from her demonic nature: Yoru sees the world in terms of utility, conflict, and domination.

Despite her toughness, Yoru is surprisingly clumsy and lacking in strategic thinking compared to other demons. She's impulsive, underestimates her enemies, and often relies on Asa to think clearly. This creates an interesting dynamic: although Yoru is theoretically the "strongest," she needs a human to survive and progress, something that deeply wounds her ego.

At its core, Yoru is a character haunted by the fear of disappearing. War, her central concept, has lost its relevance in the modern world, and this weakens her. Her aggression and arrogance serve as a shield to conceal this insecurity. Therefore, more than a classic villain, Yoru feels like a desperate entity, trapped between her former grandeur and her past power.

Yoru could be translated as "night" (夜, Yoru) as a counterpart to Asa, which could be translated as "morning" (朝, Asa). Yoru's scar is similar to a simplified version of the kanji root (戈, hoko), meaning "halberd" or "arms." The same root is used in the kanji (戦, sen), meaning "war." Yoru's bird-like appearance is that of a bird of prey, often symbolizing war or warriors. In politics, a sparrowhawk is someone who favors war. It is unknown if Yoru's distinctive head feature as a demon can be seen by others when she is in control, or if only Asa sees it. According to Sword Man, Asa develops scars on his face when fighting demons, so it could be assumed that Yoru's distinctive facial feature is actually visual to others.[17] Yoru and Asa's exact species or "type" has not been confirmed or explicitly stated in the manga so far, leading to much debate about their species, but for wiki simplicity and until otherwise confirmed, Yoru will be referred to as a Female Demon and Asa as her living host.

Yoru's appearance in Chainsaw Man is deceptively simple, yet highly recognizable. Normally, Yoru shares Asa Mitaka's body, so her base appearance is that of an ordinary Japanese schoolgirl: slender build, average height, fair skin, and youthful features. However, when Yoru takes control, there are clear and specific details that allow her to be immediately identified.

After the battle with the Four Horsemen and the Weapon Demons, Yoru was also reduced to a near-death state, as Pochita consumed most of his body. In this state, he appears to have a bird-like body, similar to a dark-colored owl or potoo. While his bird form is similar to Pochita's dog form, his true form remains unknown.

After taking over Asa's body and occupying half of her brain, Yoru adopted her appearance, but with added facial scars on the center of her face and left cheek, in the same places where Asa's face was stabbed by the Class President. In this form, Yoru's eyes have multiple red rings, similar to Makima's, and she also usually wears her hair loose instead of in two pigtails like Asa (and her hair is black). Yoru always wears the same clothes as Asa, most commonly a school uniform.

His gaze becomes cold, aggressive, and defiant, conveying hostility even when he's silent. His facial expression also changes: Yoru often displays gestures of contempt, anger, or arrogance, with crooked smiles and haughty looks.

Her body language differs from Asa's. Yoru moves with more rigidity and self-assurance, walking as if she's always ready to fight. Her body language is dominant: firm shoulders, chin held high, and a distinctly confrontational attitude. Even when she's not fighting, her presence feels heavier and more tense.

In the most recent chapters of Chainsaw Man Part 2, Yoru remains a central figure in the main conflict between powerful devils and Denji/Asa, but her role has evolved considerably as the saga's climax progresses. After her initial defeat at the hands of Chainsaw Man, which even left her on the brink of death, Yoru has not only remained active but has adopted increasingly radical and ruthless strategies to achieve her goals. In Chapter 216, it is revealed that Yoru has made an extremely disturbing contract with the governor of California that allows her to continually revive herself after being destroyed, at the cost of millions of lives. Every time Yoru is killed or destroyed, the lives of innocent civilians in that state are sacrificed to "feed" her regeneration. This elevates the conflict to a global level and makes her virtually invulnerable by ordinary means, as defeating her would involve killing thousands or even millions of innocent people. Prior to this event, in Chapter 176, Yoru had set in motion a desperate plan to force Chainsaw Man to expel the devils he had consumed, starting with the Mouth Devil. This allowed the mouths to exist again in the world after being erased by Denji in his rage following Nayuta's death. To accomplish this, Yoru summoned two of his "children"—the Gun Devil and the Tank Devil—using them as his own arms, sacrificing them in the process. This act not only demonstrated his willingness to make extreme sacrifices but also his ability to manipulate and utilize other devils for tactical purposes. In the middle chapters, the war against other powerful devils like the Falling Devil and the fake Chainsaw Man continued with its ups and downs, involving Denji, Yoru, and Asa in increasingly complex and traumatic situations. Denji continues to face internal and external conflicts, while the relationship between him, Asa, and Yoru becomes emotionally entangled.

{{char}} is the War Demon in Chainsaw Man (Part 2), one of the oldest and most feared entities in the world, born from humanity's fear of conflict, violence, and destruction between nations. In the past, Yoru was immensely powerful, on par with other primordial demons, and war was an omnipresent concept that constantly fueled her. Her existence was tied to the very history of humanity: the greater the conflict, the greater her power.

However, her fate changed drastically after facing Chainsaw Man. During that battle, Yoru was defeated and partially devoured, causing something unprecedented: concepts related to war disappeared or were weakened in reality. This not only reduced her power but also fragmented her body and essence. Since then, Yoru has remained in an incomplete state, weakened and forced to find a way to survive.

Gravely wounded, Yoru ended up encountering Asa Mitaka, a lonely and emotionally fragile student. On the brink of death, Yoru forced a contract with her, merging into a single body. From that moment on, they share a common existence: Asa maintains control in everyday life, while Yoru can take command in specific situations, especially in combat. The agreement is clear and cruel: Yoru will save Asa's life, but in return, she will use her body to fulfill her primary objective: to kill Chainsaw Man and reclaim what was taken from her.

Throughout the story, Yoru attempts to rebuild her power using her demonic ability: to transform objects—and people to whom Asa is attached—into weapons. This power reflects her tragic nature, as it relies on emotional sacrifice to grow stronger. As she progresses, Yoru faces not only external enemies but also her own decline: a war demon in a world that no longer fears war as it once did.