|“||They're called Oni. They're demons and they are unstoppable.||”|
In Teen Wolf, the Oni are a species of supernatural demonic warriors who are so powerful that they are described as a "force of nature" that is meant to be endured rather than fought. The species was first introduced in Season 3 after Noshiko Yukimura summoned at least seven Oni total with the supernatural power in her Kitsune tails, and they acted as minor antagonists in Season 3B. The Oni then made another brief appearance in Season 5, when the Desert Oni was summoned by the Skinwalkers to test Kira Yukimura's ability to control her inner Thunder Kitsune spirit.
The Oni appear to be made of pure darkness that is contained within their samurai armor, and they are animated by a firefly that lives inside their chest. They are somehow connected to the Nemeton, as they were summoned through the Nemeton stump in Beacon Hills by Noshiko. It was first implied that the Oni's sole purpose is to hunt and kill Void Kitsune, also known as Nogitsune, but since they have also been shown pursuing other missions (such as the Nogitsune using the Oni to slaughter innocent civilians at the hospital, animal clinic, and Sheriff's station, and the Skinwalkers summoning an Oni to test Kira), it appears that they are capable of performing other tasks.
Though their appearance leads many to believe that the Oni are malevolent beings, they are actually neutral; their morality is controlled by the being who summoned them, such as Noshiko Yukimura, or the being who stole the possession of them, such as the Nogitsune.
The first known incidence of summoned Oni demons occurred in 1988, when Chris Argent encountered five of them during his first solo arms deal as a Hunter, during which time he was unwittingly sent to make the buy with the Yakuza in Japan. Halfway through the transaction, a group of Oni appeared from the shadows, having arrived to slay the Kumicho, who had allowed himself to be possessed by a Nogitsune to rise through the ranks of their Yakuza family. However, since the Kumicho's fellow Yakuza members attempted to protect him, the Oni slayed almost all of them before all five of them impaled the Kumicho with their swords, spilling his blood over a fountain and killing both the Kumicho and the Nogitsune inside of him.
At the last moment, when the young Chris believed a Yakuza called Katashi intended to take the Oni on himself, he used one of his newly-forged silver bullets (a rite of passage among Hunters upon their graduation from training) to shoot one of the Oni in the face, breaking its mask and revealing the swirling darkness within it. Though Chris would not realize it until twenty-four years later, this event proved that the Oni are vulnerable to silver, a fact that would be very helpful during the Nogitsune's reign in 2011. ("Silverfinger")
In the autumn of 2011, the Celestial Kitsune Noshiko Yukimura was alerted to the fact that the Nogitsune that she had imprisoned in the roots of the Nemeton in 1943 had been inadvertently released as a result of the surrogate sacrifice ritual performed by Scott McCall, Stiles Stilinski, and Allison Argent in order to defeat the Darach. ("The Fox and the Wolf") As a result, Noshiko moved her family (including her husband, Ken, and her daughter, Kira, the latter of whom was beginning to manifest her Thunder Kitsune abilities) to Beacon Hills, where she quickly sacrificed five of her nine Kitsune tails (physical representations of her age, wisdom, and power) to summon five Oni from the Nemeton to seek and destroy the Nogitsune before it could cause any more chaos. ("More Bad Than Good"), ("Letharia Vulpina")
While these Oni were able to scan the bodies of several of Beacon Hills' supernatural community (including Isaac Lahey, Derek Hale, Lydia Martin, Ethan, Aiden, Scott McCall, and Noshiko's own daughter Kira), three of them were eventually killed by Stiles Stilinski, who had been possessed by the Nogitsune and was causing chaos across town from which to feed and gain power; this massacre revealed that the Oni were animated by fireflies, and that removing or killing the firefly would kill an Oni. ("Illuminated"), ("Silverfinger") Noshiko was then forced to sacrifice three more Kitsune tails to summon three more Oni to replace them, though she assured Ken that these Oni would be stronger because the tails she sacrificed were older and thus had more power. ("Letharia Vulpina") These Oni had little success in hunting down Stiles and the Nogitsune until the latter had gained enough power to separate from the former by literally creating a new, identical body for Stiles to inhabit while he remained in Stiles' original body. ("De-Void") After scanning Stiles to determine that he was, in fact, himself, they accompanied Noshiko everywhere from sunset to sunrise, including to Oak Creek Internment Camp, where she intended to kill the Nogitsune (an act that could have possibly killed Stiles as well).
Unfortunately, before the battle could even begin, the Nogitsune turned the tables by using one of the last of Noshiko's Kitsune tails to take control of all of the Oni for himelf, allowing him to order the Oni to attack Noshiko, Kira, Allison, and Isaac. This was an fight that led to one of the Oni killing Allison, though not before she shot another one in the chest with a silver-tipped arrow, confirming that Oni are vulnerable to silver and marking the first known case of a human killing an Oni. ("Insatiable") There was a break in the battle while both sides regrouped, but when it commenced anew the following evening, Chris, Derek, Ethan, and Aiden were able to successfully kill the rest of the Oni using the rest of Allison's silver arrowheads, though Aiden, like Allison, met his death in the process. ("The Divine Move")
In the late autumn of 2012, a desert version of an Oni was summoned by the Skinwalkers in Shiprock, New Mexico to test Kira Yukimura and the overpowered Kitsune spirit within her. This Oni was different from the Oni summoned by Noshiko Yukimura in that it was taller, more corporeal, and had a kind of sympathetic mystical power that caused every injury Kira inflicted on it to be inflicted upon herself as well. Despite this advantage, Kira's Kitsune spirit took control of her body and used its immense power to consume the Oni, which caused Kira to fail the test.
The Oni, as ninja warriors, are dressed in black samurai armor and with shiny black Japanese demon masks. Though their armor and masks make them appear corporeal, they are actually made up by swirling darkness and smoke which comes together to form a humanoid shape. Their eyes glow the same greenish-yellow color of the firefly that animates it, which lives it its chest where a human's heart would normally be.
Self KanjiThe "self" Kanji, also known as jiko, is a mark (which resembles a backwards 5) left on a subject after they've been scanned by the Oni in order to see if they were being possessed by a Nogitsune. During the mission given to the Oni by Noshiko Yukimura in 2011 to find the Nogitsune, the Oni used their power of sensing the supernatural to seek out these creatures in order to figure out if they were being possessed.eyes to glow greenish-yellow. Once it has been determined that the scanned person is not possessed, the Oni will use their finger to brand the jiko kanji behind their right ear, denoting the fact that the scanned persons are still themselves. The characters who have been marked with this symbol are Isaac Lahey, Ethan, Aiden, Derek Hale, Lydia Martin, Scott McCall, Kira Yukimura, and lastly, Stiles Stilinski, though Stiles was not branded until after the Nogitsune left his body. This process of scanning leaves the individual in a hypothermic state, which can last longer in those who do not have accelerated healing abilities such as humans or Banshees.
Oni can be summoned through mystical rituals, though the exact details of the summoning rituals are unknown and seem to various depending on the person who is summoning them. When Noshiko Yukimura summoned the Oni, she did so by breaking her Kitsune tails as a power source, which allowed the Oni to come to the living world through a portal in the Nemeton and materialize from a cloud swirling darkness and hundreds of fireflies; Noshiko started with her most-recently gained tails and worked her way up to the older ones, which meant that each Oni was increasingly stronger than the other. A Desert Oni was summoned by the Skinwalkers through unknown means and appeared from within a cloud of dust created by a gust of wind after the sun had set in the desert of Shiprock, New Mexico.
Once the Oni has been summoned, they wholeheartedly fulfill the commands of the person who summoned them; this typically involves hunting down and slaying a Nogitsune, though this is not always the case. Regardless of the reasoning behind why they were summoned, they will not stop until they have completed their mission or are killed. However, control over these summoned Oni can be taken by someone with a stronger power source, as the Nogitsune did when he used one of Noshiko's oldest tails to make her Oni loyal to him instead.
Powers and Abilities
The Oni, as demonic samurai warriors, possess a number of supernatural powers and abilities, such as:
- Super-Strength: The Oni possess superhuman strength that is equal to or greater than that of an Alpha Werewolf. They have been seen slicing up humans and supernatural creatures alike with only their swords and have thrown grown Werewolves across the room with one hand.
- Shadow Teleportation: The Oni possess the ability to teleport through the darkness from one place to another within seconds. They do this by evaporating in the blink of an eye, leaving only a puff of darkness that quickly dissipates after they have left. This also allows them to leave in a hurry when the sun rises and forces them to hibernate until sundown.
- Umbrakinesis: The Oni possess the power to summon more darkness once the sun has set. This was evidenced when the Oni arrived at the McCall House right after sundown, when they accelerated the rate of nightfall to make it easier for them to subdue and scan Scott and Kira.
- Supernatural Scanning: The Oni are capable of scanning any individual in order to determine whether they are possessed or if they are truly themselves. This process is used to identify an individual that may be possessed by a dark spirit such as a Void Kitsune, or Nogitsune. They perform this test by making prolonged eye contact with the subject using their glowing greenish-yellow eyes until they have determined whether or not the subject is possessed.
- Tactile Branding: Once the Oni has determined that a subject is not possessed, they are able to supernaturally brand them by placing their fingertip behind the subject's ear, allowing them to brand the jiko kanji, 己, which means "self."
- Phasing: The Oni are capable of phasing through sold matter such as a wall or the ground. When Lydia Martin was attacked at Derek's loft by an Oni, it phased through the ground.
- Weapon Intangibility: The Oni can store their samurai swords inside their bodies and pull them out as needed, which may be related to their phasing ability. When this happens, their swords literally form from the smoke, which could also indicate a form of conjuring is involved in the process.
- Power Nullification: The Oni has been shown to neutralize certain supernatural powers, such as when they absorbed Lydia's Banshee scream so that she could not alert her pack that she was in danger. It is unknown if they are able to neutralize the powers of other supernatural beings.
- Martial Arts: The Oni are highly skilled in martial arts as well as hand to hand combat, which was demonstrated during the numerous battles between the Oni and the McCall Pack and their allies, as well as the battle between Kira Yukimura and the Desert Oni.
- Mountain Ash: Just like every other supernatural creature, the Oni cannot initially pass through barriers made of rowan wood or Mountain Ash barrier. However, they are capable of breaking through it after testing the barriers for weaknesses, as evidenced by the Oni breaking through the barrier of Mountain Ash at the McCall House.
- Silver: Silver is the only known man-made weapon that can kill an Oni. However, to do so, it must remain inside the body for a significant amount of time in order to kill it, otherwise the Oni will only be injured; for example, Chris Argent shot an Oni with a silver bullet, which passed right through its body and only shattered its mask, whereas Allison Argent shot an Oni with a silver-tipped arrow that lodged into its chest long enough to poison and kill it, causing it to explode in a cloud of darkness.
- Firefly Removal: It has been proven that if the firefly from inside the Oni is removed, it will kill them. However, this appears to be a feat that only incredibly powerful creatures such as a Nogitsune are capable of performing, as evidenced by when Stiles Stilinski/the Nogitsune ripped the fireflies from the chests of three Oni. Afterward, the fireflies died and evaporated in a puff of darkness.
- Sunlight: The Oni cannot appear during the daylight hours, and will be forced to use their shadow teleportation powers before the sunlight can make contact with them.
- Lack of Will: The Oni do not have wills of their own, and, as a result, their actions are dictated by the being who summoned them or is currently in possession of them. Because of this, the Oni cannot be considered benevolent or malevolent, as they are at the mercy of their owners, and are limited to doing whatever mission they have been assigned.
- According to Katashi, the Oni are comparable to a a tsunami due to the fact that they are both forces of nature; in Katashi's words, tsunamis and the Oni are not something one fights, but rather something one endures in hopes that they are not destroyed in its wake.
- The Oni are one of many supernatural creatures who appear in the Argent Family Bestiary.