Keiyaku

Keiyakus are one of the defining features of the manga LORD EATER by Jahcica. It is a technique that allows a living being to use and manipulate one physical object, with a few limitations. The term "Keiyaku" can also be used in conversation to refer to said object. A person capable of utilizing Keiyaku is colloquially referred to as a "Keiyaku user" while those who cannot go by the name of "non-users". Because one can craft a great variety of parapsychological abilities through their Keiyaku, it is considered a dangerous power and the initiation and learning of Keiyakus is hidden from the public at large to maintain balance in society.

Basics
A person can only choose their Keiyaku once, and cannot change this under any circumstances (except one). A Keiyaku always retains its original form when called upon; therefore if a Keiyaku were to take any damage or to be destroyed, once it is recalled and formed again, it will be in the same state as it was originally.

Conditions
A person may choose any physical object to be their Keiyaku, with a few limitations.


 * 1) The object must be recognized by the general public. This means that a person cannot craft a weapon to loophole the ramifications of a Keiyaku to use as one. This requirement is met through the user’s thoughts; therefore, if a user were to believe an object were generally used, they would be able to use it as a Keiyaku. If a user is not sure whether or not an object is well-known, or if they later believe that the object isn't, it will not be usable.
 * 2) The object must be able to be carried by the user. A Keiyaku is formed in the preferred hand of the user, and if they are unable to carry the object after it has been formed, it is not usable. If a user were to be unable to carry their Keiyaku after they have chosen it, the Keiyaku will not be able to be formed until they are able to carry it again.
 * 3) The user must have the physical object they choose in person. When a Keiyaku is chosen, the user must have it in their hands.

Initialization
To turn an object into a Keiyaku, one must hold the object in their hand(s) and recite a phrase in the native tongue Fukyaken, which is said in the current language as "Man gyaken ito ether, senbalto kakenhavo."

Keiyakus in Society
Keiyakus are an ability known to the public at large, but only select people are allowed to develop or even possess a Keiyaku. They are feared due to the state’s constant watch for them, making them appear to be dangerous. However, some non-users believe that Keiyakus simply don’t exist and are a fabrication made by the government to instill fear into its citizens.

Keiyakus and Professions
Many users choose their Keiyaku to reflect the profession they’re in. Because a Keiyaku can be nearly any object and will retain its original form, users are able to make extraordinary advances in their professions. For example, farmers outside of Bawskee City choose their Keiyaku to be a hoe, then if they were a Jotai user, can manipulate water molecules to water their crops. Doctors in Bawskee City often transform their Keiyakus into a blood type required for a blood transfusion, then once the patient has recovered enough to be able to produce more blood, they remove their Keiyaku from the patient’s system.

Keiyakus and the State
Creating a Keiyaku without the consent of the state is against the law and often results in a life sentence, though in rare cases can result in execution depending on the lethality of the Keiyaku. The only way to prove whether or not a person possesses one is if they willingly use it, and as such if a non user pleads innocent to possessing a Keiyaku after being interrogated, the state tends to rule that they were committing perjury and convicts them anyway.

The only way to legally obtain (and know how to create) a Keiyaku is through the state. Despite this, many black market dealers are willing to explain how to create a Keiyaku for a fee, and as the creation of one is simply a verbal phrase, the spread of information is extremely fast and around a quarter of the population of Bawskee City are at least aware of the rules to creating a Keiyaku.

Keiyakus and the BHA
The Bounty Hunter Association requires every member to possess a Keiyaku and display exceptional combat abilities with it. Because of this, many Bounty Hunters were previously soldiers for the state.

Many high-profile jobs contracted to the Bounty Hunter Association list being experienced in a Kotsu type as a minimum requirement. A licensed Bounty Hunter may not reveal the existence of their Kotsu to those who do not know about it, although it is possible to relay this information in times of emergency.

Many Bounty Hunters are proficient Keiyaku users, with Fame Hall, the 7th Leader of the Bounty Hunter Association, being revered as one of the world’s most powerful Keiyaku users, as well as the Killgood Crew, a group of high-ranking Bounty Hunters known for their bizarre but effective uses of Keiyaku.

Keiyakus and Entertainment
Fight Clubs

Despite the government’s heavy watch over the possession of Keiyakus, the poorer regions of Bawskee City hold Fight Clubs in which two Keiyaku users face off, with bets placed on either side. The audience of these Fight Clubs often possess a Keiyaku themselves, and learn from each other through these battles. They are risky to participate or even watch, and many fights end up in multiple arrests.

“Stealing” a Keiyaku
A common process practiced by Keiyaku users is “stealing” a Keiyaku, in which a non-user will take hold of another’s Keiyaku and make it their own. In this situation, the non-user is granted ownership of the Keiyaku, and will possess it unless the original owner takes it back and reinitiates the process. During this time, the original owner will not be able to possess a Keiyaku or use their Kotsu. If a non-user steals a Keiyaku, then the Keiyaku is returned to the original owner, the non-user suffers no consequences and can possess another Keiyaku.

Kotsu
There are four types of Kotsu; every individual is born having one of these four different Kotsu types, but cannot progress their abilities until creating a Keiyaku. Upon learning one's own type, a student of Kotsu can set about learning to apply the technique in a unique way that suits their Keiyaku, which can develop into a unique skill.

If a user were to have their Keiyaku stolen or not be able to form it, they lose all Kotsu abilities until they are able to form it again.

An individual’s total amount of Kotsu is divided between the four types. Most users are majority one type, however some individuals known as “Multiusers” have their type spread evenly among more than one type. The divination of Kotsu has been linked to an equal spread of Kotsu types among family heritage (if a user’s father was an Ugoku user, and so was his father and mother, and their mother was a Kangaeru user, as well as her father and mother, then that user has a high chance of being a Multiuser), however this isn’t the only reason: for example Bruno Lakyuvar is equally adept as a Kangaeru and Jotai user despite both his parents’ family trees being entirely Jotai users.

Ugoku - teleportation

Kangaeru - telekinesis

Jotai - matter makeup

Ryogae - equivalent exchange

Kotsu Personality Test
The Kotsu Personality Test is a Kotsu-identification method invented by the Bawskee government that judges a person’s Kotsu type based on their personality. According to this test, all people of one Kotsu type are generally of the same personality type. This method is proven to not be entirely accurate, but is state-enforced and the only way to have your Kotsu type legally recognized. According to this theory:


 * Ugoku users are usually optimistic and positive. They don’t lie very often and rarely hide their emotions. Even in an apparently bad or difficult situation, Kotai users stay positive.
 * Kangaeru users are unemotional and stolidly calm. They often do not reveal their true motives, both because they don’t tend to talk and because of the nature of their ability. They are calm, easygoing people who are not plagued with emotional outbursts, exaggerated feelings, anger, bitterness or unforgiveness as are other temperaments. They are observers who do not get involved nor expend much energy.
 * Jotai users are strong-willed, active, extroverted, quick-tempered and impatient. Also regarded as a visionary, Jotai users are always full of ideas, a planner and goal-oriented.
 * Ryogae users are analytical and detail-oriented, and they are deep thinkers and feelers. They are introverted and try to avoid being singled out in a crowd.

Ugoku
Ugoku users are able to teleport their Keiyaku anywhere within their Hassan. The Keiyaku cannot teleport into other objects, nor can it carry velocity; however it will maintain the position it is teleported to until force is acted upon it. After being teleported, a Keiyaku is not affected by gravity until it is within reach of the user.

Ugoku is considered the simplest ability to train in, as there are few clear paths to develop. Each teleportation of a Keiyaku uses energy, and the aura of your teleportation can be increased or relocated. The size of a user’s Keiyaku determines both the space it can take up and the amount of energy required to teleport it, and as such Ugoku users tend to pick smaller objects. Notable Ugoku users include:


 * Knox Naly
 * Lord Nikolai
 * Azmi Soewarno
 * Jewel Free

Kangaeru
Kangaeru users can telepathically move their Keiyaku. Variables that factor into the amount of energy required to move a Keiyaku include the distance from user, its velocity, and the amount of force acting upon itself.

Larger Keiyakus benefit Kangaeru users, as the physical mass of the Keiyaku doesn’t affect the amount of energy required to move it (as opposed to Ugoku), and as more energy is needed to move a Keiyaku when force is acted upon it, the size and shape of a larger Keiyaku creates more resistance against objects. Kangaeru cannot change the mass of a Keiyaku without resistance from other objects.

The amount of energy needed to telepathically move a Keiyaku is equal when the Keiyaku is within one's Hassan, and increases exponentially the farther from the Hassan it gets.

Notable Kangaeru users include:


 * Zed Loec
 * Fame Hall

Jotai
Jotai users can change the makeup of their Keiyaku. Keiyakus will almost always be formed in solid form as it is the only state of matter that a user can physically hold, but after forming their Keiyaku, a Jotai user can change it into any liquid, gas, or plasma. Jotai users must have experience with a specific state of matter to be able to harness it.

Jotai users are also able to manipulate states of matter within their Hassan. This technique requires the user’s base Keiyaku to be of the same matter state as the matter they are manipulating.

Notable Jotai users include:


 * Yuki Akatsui
 * Keiichiro Goulbourne
 * Kusunobi Miller

Ryogae
Ryogae users can reshape their Keiyaku into another object with the same mass. Matter cannot be created nor destroyed when changing. The user’s Keiyaku must be in their hands while changing. Ryogae users often pick an object composed of a single element such as a boulder or a tree stump to be their Keiyaku so changing it is simpler; however intelligent Ryogae users have chosen objects with multiple elements for more diverse combat.

Ryogae users, similarly to Jotai users, are able to reshape the matter within their Hassan. The farther away the chemical makeup of the matter they are manipulating is from the chemical makeup of their Keiyaku, the more effort is required to manipulate it, ex. a user whose Keiyaku is a sword made mostly out of metal/iron will have difficulty manipulating an object made of lead.

Notable Ryogae users include:


 * Kyoto Kaz
 * Citra Zefanya
 * Tower Balling

Multiusers
Multiusers are users who are equally skilled in multiple types of Kotsu. Everyone is able to use Kotsu to some degree, including not just their own type. The strength of a specific Kotsu varies by person, as does the strength of every type. Multiusers are equally adept in two or more categories, no matter their overall strength.

A common misconception is that because Multiusers are equally skilled in more than one category, they inherently have a greater skill ceiling than other users. This is not true, as the statement that they are adept in more than one category by itself infers that they do not have a large amount divided into one category of Kotsu; however, this statement is almost an antithesis in of itself, as to be considered adept in more than one category, one must have a high usage of Kotsu, therefore the misconception is, in a bizarre way, true to some degree.

Another misconception is that Multiusers have their divination split equally between multiple types. Although this is the textbook definition of the type, it is not the de facto meaning of it, as their are users who can have a higher divination in one category compared to another, but decide for a multitude of reasons to practice in a lower divided category, eventually to the point where it becomes equal to their primary Kotsu type.

Multiusers are not a type that can be easily identified, as there is no definitive way to compare a Kotsu type to another, so most Multiusers have some variation of strength in between types.

Notable Multiusers include:


 * The 4k Crew
 * Zel Rae Don
 * Bruno Lakyuvar

Core Principals
The core principals of Kotsu are principals that apply to every type and can be taught to any user.

Hassan
Hassan is the aura that every person capable of utilizing Kotsu emits. Hassan is important for every Kotsu type, each for different reasons, albeit some more similar than others. The color of a user's Hassan is based upon their emotion, however color schemes for each emotion differs for each individual and is based on the feelings they perceive towards them. Skilled Hassan readers are able to determine an individual's emotion colors based on the situations they are faced with and how they change. If multiple Hassans were to overlap, the colors of each Hassan would blend.

Once one creates their Keiyaku, they are able to perceive any quality of Hassan as long as it is formed. If one were to lose possession of their Keiyaku, they would lose their Hassan, as well.

Kakusu
A skill users can pursue is the resizing of their Hassan. In situations where a user doesn't want their Hassan to be recognized, they are able to resize it, even back to its original, almost invisible form. This technique is called Kakusu (隠す, Kakusu—lit. "Hide"). Kakusu cannot make your Hassan completely disappear, and shrinking your Hassan comes with the risk of the weakened use of Kotsu.

Nejire
Nejire is the ability to change the color of one's Hassan. A user capable of changing his view of colors as their relation to emotions is able to change their Hassan, as well.

Meisai
Meisai is a subdivision of Nejire in which a user recolors their Hassan entirely to fit the colors surrounding them, making their Hassan unnoticeable. If a user completely achieves Meisai (which involves the knowledge of Soryoku, to an extent), their Hassan is rendered completely invisible, while still being usable.

Soryoku
Soryoku is a Hassan technique that involves a user outputting an immense amount of energy to increase the size and quality of their Hassan, usually to a translucent level. This technique is usually used to overwhelm an opponent by having them perceive only the user's Hassan, and if a user were skilled enough, could manipulate their Hassan to be completely opaque and appear as a different environment.

Training Exercises
When a user first creates a Keiyaku, their Hassan is an almost invisible thin line surrounding their physical frame. From there, one can make the decision for their Hassan to stay attached to their body, or to detach it and be able to harness it easier, with the consequence of it remaining in one place.

Hassan doesn't necessarily need to be consistently practiced, as users are capable (and technically forced to) perceive it at all times, and a user's Hassan will only weaken if the physical strength or overall energy of the user is weakened, as well. As such, the power of one's Hassan is directly related, but not limited to, the physical strength of the user.

Seido
Seido (精度, Seido—lit. "precision") is the overall fluidity of one's motions with their Keiyaku and its relativity to the user's Kotsu. Seido is not necessarily an ability in of itself, but rather a sort of scale that determines the skill of a user with their Keiyaku and Kotsu, as the more fluid their motions are and the easier they can combine their Keiyaku abilities with those of Kotsu, the higher their skill is supposed to be. Therefore, the higher the quantitative amount of Seido one has is directly proportional to their overall expertise.

Recognized Ugoku Abilities
Mabataki is one of the most difficult techniques an Ugoku user can use, and increases exponentially in difficulty with each new form added on to itself. It is a simple concept, yet requires tremendous amounts of energy to perform. When one uses Mabataki, they teleport their Keiyaku back and forth between multiple places at once, as fast as they are able to, and if one were skilled enough, could teleport their Keiyaku faster than the human eye can perceive, making it appear as if a user has multiple Keiyakus. This can confuse and scare off both non-users and inexperienced users (and even skilled users, if they were under the presumption the user were well-developed in Ryogae), but is also can work against veteran users, as they cannot tell where the Keiyaku will actually be. It can also be a sort of alert system, as an object that comes into contact with a "copy" will cause it to not be able to reappear, as there is not enough space in its location to teleport to.

Very few Ugoku users are able to perform Mabataki for extended periods of time, the only three known users being Lord Nikolai, Knox Naly, and his father Xavier Naly. In Lord Nikolai's instance, Mabataki was used as a defense mechanism for over an hour, as a means to block gunshots and provide a shield around himself during the S-Tier Raid. Knox used Mabataki multiple times, originally only using it to create one "copy" and only for brief periods of time, and eventually creating 6 copies after losing his sanity, using all of the energy his body could produce at the time and effectively exhausting him to the point of inducing a coma. Xavier used Mabataki to protect himself and his wife while on the run from the Cheka after an unsuccessful coupe. In all three situations, the user's excessive use of energy while performing Mabataki was one of the primary reasons that led to their demise.

Tamerau (ためらう, Tamerau—lit. "hesitate") is an Ugoku technique in which a user purposely uses little to no energy while teleporting their Keiyaku to make it take a longer amount of time to teleport. Tamerau is used in instances where a user will want to place their Keiyaku in specific places early on, and they will have more energy while performing a task as the energy required to teleport the Keiyaku is spread throughout the time in between teleportations, as opposed to an instance loss.

Recognized Kangaeru Abilities
Hobaringu is a technique that originated in feudal Jopan in which a Kangaeru user uses their Keiyaku as a means of transportation by applying pressure upwards onto it while stepping on it. There are two types of Hobaringu, one in which the user stays static and and moves the Keiyaku to move themself, and the other in which the user moves themselves as well as their Keiyaku, having it reach their feet every time their step has finished.

Hobaringu is a relatively difficult technique to learn, as the user must be able to not only telepathically hold their own weight, but carry it reasonable distances. When Zed first attempted to learn it, he could not carry himself any farther than five steps. The technical counterpart is also difficult, as for the first type one must intuitively know the max speed able to carry themselves without falling off their Keiyaku, and for the second one needs to know the distance between their steps, as well as to change their stepping distance if they were to raise or lower their path.

Recognized Jotai Abilities
Yoki is a common Jotai technique that involves a user's Keiyaku being both the substance the user wants to manipulate and a vessel to contain the substance. Using this technique, a user will transform the substance within the vessel while keeping the vessel's base form, able to transform a potentially dangerous substance safely.

Yuki Akatsui uses Yoki in the form of a syringe as his vessel and O- blood as his substance. He originally converts the O- blood to sleep anesthetic, which doesn't necessarily require the use of Yoki, but eventually converts it into toxic acid.

Recognized Ryogae Abilities
Henshin is a loosely defined term in which a Ryogae user transforms their Keiyaku into multiple weapons in combat to allow for more diversity. To use Henshin is a blanket statement, as most Ryogae users who use their Keiyaku for combat perform this technique often, some not even aware of its name or existence. Because of this, Henshin became a sort of mantra for Ryogae users rather than an actual technique, showing that if one were to say they used Henshin, they used their Keiyaku for combat.

Combat Training Exercises
As with most things in life, one must train for a considerable amount of time to become adept in both Keiyakus and Kotsu, and the amount of time and effort put into growing one's abilities varies by person.

Keiyakus and Kotsu
Because of the nature of Keiyakus, the training required to become adept with one greatly varies, as there is an unlimited amount of possibilities when creating one. Many users creating a Keiyaku for combat often practice with many weapons to determine which one suits them, then practice Keiyaku training without actually forming their Keiyaku. Standard training often starts with exercising the forming and vanishing of the Keiyaku and developing the awareness of the user's surroundings in order to form it, then ventures off into other paths.

The four branches of Kotsu all have different training methods, with some being somewhat related to each other and others being entirely different. Many users develop the core principals of Kotsu, then develop principals of multiple Kotsu types, and form unique abilities from there.

Ugoku Training
Ugoku users often start with increasing their Hassan to the size of their Keiyaku, then practicing teleporting their Keiyaku within this boundary, making sure to increase the amount of energy used in each teleport over time. After comfortably teleporting multiple times, the user will increase their Hassan to its natural size, then continue to teleport their Keiyaku, sending it farther and farther from its base position. Eventually, they will begin to practice combat combinations, teleporting their Keiyaku as they fight. This is where the training reflects the object chosen to be a Keiyaku and diverges into originality.

Progression and Potential
While all living things are capable of possessing Hassan and all humans (as well as possibly beings of other species) are able to master Kotsu, some excel at its usage more than others. What exactly factors into potential is for the most part a mystery, but it appears to be predominantly a congenital factor, since statistical estimations about its rarity can be made and evidence points against it changing over the course of one's life. The rubric of "potential" or "talent" entails both the maximum degree of mastery that one could achieve and the speed of one's learning, which seem to be directly proportional: the faster one learns, the higher their upper ceiling is assumed to be.

Of course, potential alone does not ensure that one will grow into a powerful Kotsu user, with one's regimen of training being fundamental in this regard. Furthermore, talent does not guarantee that one will progress in all areas of Kotsu with the same ease. One's growth can also be stunted by training in the wrong Kotsu types, which is a common mistake within Bawskee City.

Origination of Keiyakus
It is revealed to Zed Loec that the phrase "Man gyaken ito ether, senbalto kakenhavom," which is used to create a Keiyaku, translates in Fukyaken to "With the creation of this weapon, I damn myself to hell". It is unknown where Keiyakus originated from, but it is speculated that they started in Fukyaku, as the Fukyaken claim their god named Tyler, the Creator, gave humans Keiyakus as a test to see if their morals would stand true in the face of a weapon of mass destruction.