Four Horsemen

The Four Horsemen (４の) are a quadrumvirate of powerful Devils: the Control Devil, the War Devil, the Famine Devil, and the Death Devil.

Makima, revealed to be Control, was the first Horseman to appear, and she made reference to the other three well before any of them made their debut. The four are some of the most prominent Devils featured in the Chainsaw Man manga, with Makima being the main antagonist of Part 1 of the story while the other three (along with Nayuta, Makima's reincarnation) are featured in Part 2.

Overview
The Horsemen are four particularly powerful Devils who take on the appearance of human females and refer to themselves as "sisters". Death is the eldest and most powerful, Fami (Famine) is the second-eldest, and Yoru (War) along with Nayuta (Control) are the youngest. While Nayuta is currently the youngest of the four as Makima's recently born reincarnation, it is not explicitly confirmed if Fami and Yoru are older than Makima was.

Together, the sisters are known to have engaged in a particularly brutal battle in Hell against the Devil most feared by other Devils: "Chainsaw Man". The Horsemen seem to be the only entities in the world (Devil or otherwise) who still remember the names of the Devils devoured by Chainsaw Man, such as the Nuclear Weapons Devil, the World War II Devil, the Nazi Devil, and others. However, it is unclear how far these memories go: Makima, the Control Devil's previous incarnation, could remember the names of devoured Devils but admitted that she could not recall them beyond the sight of them fighting Chainsaw, and that even those memories were starting to fade; the next incarnation, Nayuta, appears to bear no memories from her predecessor's life.

Intergroup Relations & Ambitions
Despite their past collaboration in fighting Chainsaw Man, the Horsemen sisters are not a cohesive unit, each member pursuing different goals and agendas that tend to clash, yet which as a commonality involve Chainsaw Man in one way or another:
 * Makima, the former Control Devil, posed as a human Devil Contractor working for Japan's Devil Hunter organization, intending (after being the first to find Pochita) to bring the Chainsaw Devil under her control in order to wipe out her sisters, to get rid of their very concepts and (supposedly) create a better world; Makima went as far as to claim that she was Chainsaw Man's fan due to his incredible power and chaotic violence, to the point that she would not mind being devoured by him herself.
 * Yoru, the War Devil, intends to find Pochita and battle him again so as to slay him, in a seeming revenge plot for him eating part of her (plus other Devils that contributed to War's power, like the WWII and Nuclear Weapons Devils), while avoiding her sisters (or at least Fami) in the process.
 * Fami has dedicated herself to opposing the apocalypse prophesized by Nostradamus and, by her own word, save humanity. She seeks to prevent the apocalypse by killing her elder sister, Death, and enslaving her younger sister War to aid her in this endeavor (specifically wanting to empower both War and the Chainsaw Devil to be able to stand up to Death when she appears). Fami at different points tried recruiting both Yoru (War) and Nayuta (Control) for her plot.
 * Meanwhile, Nayuta has been taken in by Denji (Pochita's current host) and does not care to involve herself with her sisters' plans, preferring to study like a human child while living with Denji (and also admiring Chainsaw Man, wanting to see him in action as a Devil Hunter).
 * The Death Devil's current agenda is unknown, although if Nostradamus' prophecy is to be believed, she is expected to try to bring about the end of humanity, thereby ushering in the Age of Devils on Earth. If (and how) Chainsaw Man would be involved in Death's ambitions is unknown.

Personalities
The Horsemen stand out among Devils not only for their scheming tendencies (especially in the case of Control and Famine) but also their very humanlike dispositions, propensity to pose as humans, and willingness to integrate into human society in favor of their goals. They all have distinct personalities, notably maintaining a veneer of amiability towards humans despite ultimately being extremely selfish.

Makima heavily involved herself in Japan's Public Safety and, pretending to be human, almost always maintained an aura of compassion and politeness in front of people — that is, until she began betraying her closest subordinates in pursuit of her secret ambitions, at which point she revealed herself to be callous, domineering, and Machiavellian as befitting "Control" (not to mention the countless human lives that she was willing to sacrifice); Makima did mention to Kishibe that she was aiming to kill her sisters to better the world for humanity, though given her actions, the truthfulness of this statement might be called into question. War, in contrast, is loud, touchy, immature, and belligerent, befitting her nature as "War". Famine is very calm, mannered, and polite to everyone, but unlike Control does not even bother to hide her ill intentions for Asa Mitaka; additionally, though claiming to want to save humanity from extinction, she appears consequentialist (like Makima) in so far as she is willing to wreak global havoc to do so. Nayuta, the current Control Devil, has several childlike tendencies matching her current appearance, in terms of behavior and speech, though she has also exhibited domineering tendencies and can be rather perceptive.

None of the Horsemen seem to have the common Devil desire for human flesh, eating human food instead. Fami appears to be partial to fast food and has expressly named Chinese food and pizza as good enough reasons for why human civilization should be preserved, which Nayuta agreed with. The sisters also seem to have an affinity for bread.

As a shared quirk, the Four Horsemen are face-blind, with Fami stating that "we sisters have no interest in faces--human or devil". Long before revealing her true nature, Makima hinted at the fact that instead of discerning faces, she went by smell, something later confirmed by Denji, who noted that Makima never actually remembered peoples' faces, including his. Nayuta, in turn, seems to have inherited Makima's acute sense of smell. Yoru likewise noted that she had not recognized Fami due to it being too long since she last saw her, and both she and Famine (like Makima) are apparently unable to discern Denji-as-Chainsaw Man from Pochita (in his true form) by anything besides color, despite them looking very different. Whether all the four sisters perceive others via scent is unknown.

Appearances
All Four Horsemen are female, appearing as young women and/or girls.

Though they differ from another appearance-wise and may change their shape upon reincarnating, they look fully human to a degree rarely seen with full-fledged Devils (at least while in the Human World), to the point of being able to pass themselves off as regular humans without being found out and thus seamlessly integrate into society. Whether Death is an exception is unknown, since she has yet to appear, and if the Horsemen's original forms in Hell are the same degree of humanlike is also unconfirmed. Yoru the War Devil was seen taking the shape of a small, dark owl while in a weakened state, before subsequently possessing the body of a teenage girl (and being distinguished in said body by her ringed eyes and facial scars that manifest whenever she is in control).

All Four Horsemen have uniquely colored eyes whose irides are split by concentric rings.

Power
The Four Horsemen embody some of humanity's greatest fears and thus count among the strongest of Devils. The only Devils known match and/or surpass them in power are Chainsaw Man (whom the four brutally fought in the past), the "Primal Fears", and perhaps the Gun Devil at the very height of its power. Of the four, only Death herself — the eldest and strongest Horseman — is confirmed to be a Devil of "Primal Fear" status, and her younger sisters do not seem to command that same level of fear; the Eternity Devil, for instance, did not hesitate to curse out Fami when she went against their deal.

Makima, the first Horseman to appear, was also the first to showcase her power, proving to be an immensely powerful Devil who was feared the world over, by humans and Devils alike, and whom various nations on Earth had all but given up opposing. With sufficient preparation (that is, after subjugating enough Devils) Makima was able to overpower the Gun Devil at its strongest, while it was empowered by a Contract affording it one year of lifespan from every American; she did fail to deal a killing blow and prevent the Gun Devil's escape, however. Using her "Control" power to force various humans, Devils, and Fiends into Contracts, Makima was able to acquire a wealth of abilities; her Contract with the Japanese Prime Minister also made her nigh-unkillable, as any physical harm done unto her was transferred to random Japanese citizens; hence, she had a near-limitless stock of extra lives. Consequently, Makima proved herself able to pressure and even defeat Chainsaw Man, though only after the latter's drastic weakening due to humans' declining fear of him. Makima also managed to somewhat oppose the primordial Darkness Devil, being able to slightly injure and draw blood from the latter, though at the cost of her arm and while merely trying to retrieve her allies from Hell.

Makima's reincarnation Nayuta, though not yet as powerful, is shown to have a complete grasp on how to use her "Control" powers, with her sister Fami valuing her power enough to try to recruit her for her cause.

The War Devil Yoru, though having the potential to be incredibly powerful in her own right, is currently weakened due to her past battle with Pochita (who ate a piece of her) and the world having forgotten war's terrors since WWII. Not only is Yoru subject to unique limitations while possessing Asa's body, such as being unable to take her over when Asa is stricken with fear, she also lacks raw power. Since the strength of her weapons scales to the amount of guilt that Asa feels about creating them, Yoru claims that only Asa can create strong weapons. When faced with the primal Falling Devil, Yoru (unlike Makima against Darkness) felt that she had no chance in her current state, opting to flee on sight. Still, Fami believes that, if humanity's collective fear of war is heightened to its max, Yoru (together with Pochita) could be able to stand up to the Death Devil herself.

Fami, though having yet to be seen in a direct combat scenario, is shown to be very powerful too, and exceedingly resourceful in much the same way that Makima was. Her power to lock those who are hungry/starved into her servitude was shown to work even on a Primal Fear Devil, as she was able to force the Falling Devil to do her bidding and summon her from Hell to Earth. As noted by Barem Bridge, Fami has several extremely valuable Devils as her pawns: from the aforementioned Falling Devil to the Eternity Devil, to the enigmatic Fire Devil.

As revealed by Nayuta, the Death Devil (the eldest Horseman sister) is in fact a "Primal Fear" Devil herself, and not just any but the so-called "Great King of Terror" whose name is feared most of all. Hence, Death is the strongest Devil in existence whose advent on Earth is foretold as part of Nostradamus' prophecy, ushering in the apocalypse that would end humanity. Fami aims to induce global chaos specifically directed at reigniting humanity's collective fear of War and Chainsaw Man, so that both Devils may grow strong enough to possibly stand up to Death.

Abilities
As with all Devils, the Four Horsemen are endowed with abilities corresponding to their embodied concept. Coincidentally, the three Horsemen shown so far are able to exert control over things (living and nonliving) in one way or another, with different conditions attached:
 * The Control Devil's core ability is to control whom or what she deems inferior, with Makima stating "I have the power to control those I consider to be of lesser rank than myself" (i.e., weaker). Her potential targets range from humans to small animals, to Devils, to Fiends, to Hybrids. Even precise control over someone's brain, including manipulating memories and perception, is possible for the Control Devil.
 * The War Devil can turn anything she believes is "hers" (her property) into her weapons, from objects to lifeforms. This ability, when channeled through Asa Mitaka, depends on guilt: the more guilt Asa feels about creating a weapon, the stronger it will be, meaning that while Yoru possesses Asa, only Asa can create strong weapons. In this context, the concept of Asa's ownership is bound only by her own perception no matter how illogical.
 * The Famine Devil can turn those who are "hungry" into her "pawns" and have them do her bidding, potentially even a Primal Fear Devil.
 * If the Death Devil has some power of control is unknown.

Past
Together, the Horsemen sisters are known to have engaged in a particularly brutal battle in Hell against the Devil feared most by other Devils: "Chainsaw Man" (aka Pochita). For exactly how long is not revealed, although going by Yoru's words, it may have been for at least 50+ years since she mentioned how she was weakened by the absence of wars since WWII, following her fight with Pochita. However, in the midst of their final confrontation in Hell, Pochita mysteriously vanished. Despite searches conducted by the Control Devil, Pochita could not be found. Unbeknownst to the Four Horsemen, this was because Pochita had changed forms on the verge of death and escaped to Earth; this is when Denji and an injured Pochita met.

Sometime after this battle, the Horsemen arrived on Earth as well, apparently parting ways. The Control Devil assumed the identity of a human, "Makima", who became the head of Special Division 4 of Japan's Public Safety.

The Death Devil's whereabouts remain unknown, though it is implied that she has yet to appear on Earth, her advent being what Famine seeks to prevent in the present time.

Gun Devil arc
Makima's status as the Control Devil is revealed during her fight against the Gun Devil.

Control Devil arc
Makima reveals the existence of the Four Horsemen amid her fight against Chainsaw Man, describing how she, the other three Horsemen, and the Weapon Devils fought against Pochita in Hell until the battle abruptly ended, when Pochita vanished before their eyes. With the Weapon Hybrids present, she announces that the interrupted battle can finally be brought to an end, as she orders the Hybrids to attack Chainsaw Man.

After seemingly succeeding at defeating Chainsaw Man and seizing control over him, Makima is suddenly sliced open by Denji with a chainsaw. Through a loophole, Denji renders the Devil Contract Makima had with the Prime Minister of Japan that gave her nigh-immortality null and kills her by eating her entire body.

The Control Devil is soon reincarnated as Nayuta, a young girl from China. Kishibe, who discovered her, brought her to Japan where he tasks Denji with taking the girl in and raise her right, so as to prevent the rise of another Makima.

Justice Devil arc
Quite some time after Makima's downfall, the War Devil — weakened from her battle against Pochita and reduced to a diminutive, owl-like form — appears in front of a dying Asa Mitaka, after the girl is murdered by her jealous classmate out of the latter's belief that it would secure her the affections of their teacher, Mr. Tanaka. The War Devil offers to save Asa's life, in exchange for control over her body. Mitaka takes this opportunity, allowing the War Devil to assume control of her body. The War Devil immediately slaughters Asa's murderer as well as her teacher. Seeing a Chainsaw Man poster nearby, the War Devil vows to make Chainsaw Man "vomit nuclear weapons back up". War reveals that, having left Asa's brain intact, the latter's self has been preserved, causing the two to share one body, and consequently names herself "Yoru" (meaning "Night" in contrast to Asa's name, which means "Morning").

Shortly after, the Famine Devil (nicknaming herself "Fami") is revealed to have assumed the identity of a high school student at Fourth East, as a member of the school's Devil Hunter Club.

Falling Devil arc
Hirofumi Yoshida reveals the "Prophecy of Nostradamus" that foresees a coming apocalypse, during which the so-called "Great King of Terror" is to descend on Earth to usher in the end of the age of humans and the dawn of one where Devils rule (later revealed to, in fact, refer to the coming of the Death Devil). The Horsemen's attitudes towards said prophecy are shown to vary — with Famine actively working against it and wishing to preserve humanity, Control seeming disinterested, and War having not yet actively involved herself in any scheme regarding it.

When the primordial "Falling Devil" arrives from Hell to go after Asa and Yoru, the latter correctly guesses that Fami is involved. Indeed, Fami herself eventually reveals that she intended for the Falling Devil to feed Asa and Yoru to the Justice Devil and have her sister starved in its belly so that she may become Fami's pawn, to aid in the latter's plot to prevent Nostradamus' prophecy. Nayuta declines Fami's request to work with her.

Current arc
After her attempts to starve the War Devil failed, Fami with the help of Haruka Iseumi and Barem Bridge founds the Chainsaw Man Church, which quickly grows into a powerful organization with tens of thousands of members, frequent TV appearances, and political donations. Following a tense conversation, Fami manages to recruit her Horseman sister Yoru and Asa into the church, turning them both into a national celebrity to serve as a public face for the church. Besides the War Devil, the church also counts various Weapon Hybrids among its ranks.

It is later revealed that Fami, thanks to her many Devil connections, was able to make an estimated 350,000 Chainsaw Man Church followers worldwide enter Contracts with the Fire Devil, transforming them into pseudo-Devils resembling Chainsaw Man to begin inciting global chaos. This, per the plan of Fami and Barem Bridge, is for the purpose of raising humanity's collective fear of both the Chainsaw Man and War, to make both Devils strong enough to stand up to the "Great King of Terror" — Death — whose arrival on Earth (per Nostradamus' prophecy) is fortold to happen in six months' time, and which Fami and Barem aim to prevent in order to save the human race.

Trivia

 * The Four Horsemen are based, in name and concept, on the Four Horsemen of the Apocalypse (Japanese: の) from Christian eschatology, appearing in John's Book of Revelation (6:1–8) of the New Testament. Per some interpretations, they are thought to be referenced in the Old Testament's prophetic Book of Zechariah and in Ezekiel.
 * Per the scripture, these four figures are to set a divine end-time upon the world as harbingers of the Last Judgment: they appear with the opening of the first four of God's Seven Seals to release the Apocalypse, as God's punishment. They are usually interpreted by modern scholarship as Conquest (the White Rider), War (the Red Rider), Famine (the Black Rider), and finally Death (the Pale Rider, who is the only one explicitly named in the Revelation).
 * The Horsemen's order of appearance in the scripture mirrors the order of the corresponding Devils' appearance in Chainsaw Man: first shown was the Control Devil (Conquest), followed by War and then Famine, with Death having yet to appear.
 * Under one interpretation that has appeared since the early 20th century (esp. prevalent in modern pop-culture references to the Four Horsemen), the first Rider is called Pestilence instead of Conquest — associated with infectious disease and plague. While the exact origin of this interpretation is unknown, some assume a reason to be that scholars found Conquest and War to be too similar/overlap. Coincidentally, the White Rider is described as carrying bow; bows and arrows have been associated with disease since antiquity, with arrows thought of as carriers thereof (esp. the plague) due to oft being laced with poison.
 * While Makima can control whichever creature she deems inferior to herself, like animals, she has been shown to teleport herself by specifically using rats as a medium, which are creatures prominently associated with disease.
 * The term "Horseman" is traditionally rendered as Kishi (騎士) in Japanese bible translations, the gender-neutral term for "Knight".
 * Before her reveal as a Horseman, Makima was already heavily implied to be one due to her and the biblical "Conquest" Rider sharing the same name: "Conquest" being rendered as Shihai in Japanese.
 * The ringed eye design of the Horsemen — and Nayuta's character as a whole — are inspired the character Nayuta from Tatsuki Fujimoto's pre-Chainsaw Man one-shot, Yogen No Nayuta.
 * In said one-shot, Nayuta was a demon child prophesized to start the apocalypse, further emphasizing the reference in relation to the Four Horsemen.
 * The ringed eye design is not solely indicative of the Horsemen, however: the Fox Devil and Future Devil are prime examples of other Devils having such an eye design.