3 Chapter 3

Aura is the life energy produced by all living bodies, it is vital for survival and directly linked to one's stamina. The points on the body from which aura flows out are called "aura nodes". Additionally, aura is invisible to non-Nen users, it can only be seen after the aura nodes in the eyes are opened. Nonetheless, sensitive individuals can feel its presence without being aware of its existence.

A few months into their search Feitan and Valeer found a man by the name of Snekk to teach them about nen. Snekk was 6'2 with dirt blonde hair, grey eyes, and a scar by his mouth. He was a mercenary and noticed their capabilities and in exchange for teaching them the basics they had to work for the info. Both the boys didn't mind as this allowed them to not only go places and see the world but Feitan got to kill a variety of people and Valeer got to further strengthen his technique.

In normal conditions, the aura from all parts of the body tends to flow together, producing one mass of energy. This happens without the individual's awareness, typically resulting in aura slowly leaking away from the body constantly without exceedingly harmful consequences and stemming up and off the top of the head. On the other hand, if someone whose aura nodes are fully open doesn't attempt to close them or control the flow of their aura, they'll soon grow so exhausted that they'll be unable to stand or even lose consciousness. Learning to control one's aura nodes is the first step to becoming a Nen user.

The first thing Snekk did after opening their Aura nodes was teach them Ten. People who have not trained in Ten will leak aura similar to water vapor boiling out from a kettle. It has been described as feeling like a warm, viscous fluid at rest, whereas powerful, refined auras produce a sensation that feels akin to needles pricking into the skin. Hostile aura generates extremely unpleasant sensations, which can cause a non-user to halt in their tracks and be unable to walk towards the source as if a wall had been erected in front of them.

"Since every living being emits aura subconsciously, learning to sense aura is a useful skill for those who are trying to track down living things or searching for non-living things that have been infused with aura. An experienced user of Nen can judge the location and relative strength of their opponents by reading the output of their aura. On the other hand, skilled Nen users can also regulate the flow of their aura, so they appear to be beginners or regular individuals." said Snekk before pausing

"While all living things possess aura and all humans (as well as possibly beings of other species) can master Nen, 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."

During the first year, Snekk taught them Nen of the Flame. Nen of the Flame is sometimes used in Shingen-ryu kung fu as a precursor to learning actual Nen. They are mental exercises akin to meditation that strengthen one's force of will. Regular practice can smooth the flow of one's aura. The Four Exercises of Nen of the Flame are as follows:

Ten ("Point"): Focus the mind, reflect upon the self, and determine the goal.

Zetsu ("Tongue"): Put it into words.

Ren ("Temper"): Intensify your will.

Hatsu ( "Release"): Put it to action.

After unlocking their aura nodes, individuals need to master the art of preserving their aura within their body and preventing it from dissipating. This preservation technique, known as Ten ("Envelop"/"Shroud"), involves keeping the aura nodes open while allowing the energy to circulate around the body rather than escaping. Once mastered, Ten creates a subtle shroud enveloping the user, akin to the sensation of standing in a lukewarm, viscous fluid. Similar to skills like swimming or riding a bike, once acquired, the proficiency in Ten becomes ingrained and enduring.

Despite its elementary nature, Ten holds paramount importance, especially when combined with Ren, as it significantly influences the strength and smoothness of a Nen user's aura flow. This technique not only sustains a youthful vigor but also mitigates the aging process by preventing energy from leaking away. Ten serves as a fundamental defense against emotional Nen attacks and provides limited protection against physical assaults, although it becomes less effective against aura-enhanced attacks. With consistent meditation and practice, individuals can enhance the quality of their Ten, eventually maintaining it even during sleep.

While Ten enables a user to retain their aura within their body, Zetsu ("Suppress"/"Null") takes a more drastic approach by completely halting the flow of aura from their body. By closing all aura nodes, the user can cease the outflow of their aura, resembling the shutting off of water from a valve, rendering their presence challenging or even impossible to detect.

Closing the nodes in their eyes not only deprives the user of the ability to see aura but, by eliminating their own aura surroundings, heightens sensitivity to the auras of others. This heightened perception allows Zetsu to counter In, although such usage is not recommended. This technique proves particularly advantageous in tracking others, making it easier to follow someone while evading the notice of fellow Nen users. However, there are alternative methods to sense a person concealed with Zetsu; aside from relying on the efficacy of the five senses, individuals with keen perception can detect the gaze of others, even if they might struggle to discern the position and number of observers. Additionally, if Zetsu is activated within a certain range of a Nen user, the disappearing presence may be noticeable, especially if the Zetsu user possesses potent aura. Although Zetsu doesn't directly affect vision, activating it in front of others can create the illusion that the user has become transparent.

Beyond its concealment utility, Zetsu can also serve as a means to alleviate fatigue by fully containing the body's external aura layer. However, this comes with a risk, as the technique leaves the body defenseless against any aura attack. Even a minor attack enhanced with Nen can inflict significant damage. Since the meager protection offered by Ten is absent, a Zetsu user becomes particularly susceptible to hostile emotional attacks, making their mind as vulnerable as their body.

Ren ("Refine"/"Enhance") involves channeling a significantly larger amount of aura compared to Ten, projecting it explosively outward. This amplification enhances the user's physical strength and durability while creating a substantial reservoir of aura for the utilization of advanced techniques or individual skills, albeit at the cost of expending the accumulated aura. While Ten is primarily defensive, Ren serves as its offensive counterpart, providing not only increased offensive capabilities but also significantly bolstered defensive abilities.

By infusing one's Ren with hostility, a Nen user can emit a phenomenon commonly known as "bloodlust." Prolonged exposure to such malevolent Ren can induce uncontrollable dread, paralysis, and, if experienced without the protection of Ten, even death. Conversely, a neutral Ren is rarely perceptible to non-users. Since Ren showcases a user's power, it can also intimidate other Nen practitioners by offering an approximate gauge of the user's raw strength; when someone asks to "show me your Ren," they typically seek a demonstration of one's training achievements, such as a Nen ability, rather than the Ren itself. In most instances, Ren reflects the user's hostility involuntarily, leaving faint traces in the environment even after the Nen user has departed the scene.

One can enhance their Ren through training to extend its duration and increase the available aura. It is said that dedicating one month of training can extend the duration of one's Ren outside of combat by 10 minutes. Properly timed, Ten can be employed to contain the aura generated by Ren.

Hatsu ("Release"/"Act") represents an individual's distinctive expression of Nen. While its characteristics are influenced by the Nen user's natural Nen category among the six available, Hatsu is not confined to these influences. It serves as the means by which a Nen user projects their aura to accomplish a specific function, giving rise to a unique and specialized paranormal ability colloquially known as a "Nen Ability" (or simply referred to as "Ability").

A well-crafted Nen ability mirrors an individual's character and unique traits, irrespective of its intricacy or simplicity. The crucial factor is that the ability resonates with the user on a personal level; gut instincts play a pivotal role in the development of Nen abilities. Moreover, the ideal approach involves creating a unique ability from the ground up. While it is possible for anyone to learn an ability achieved through Nen, true mastery of Nen eludes those who merely copy someone else's abilities. In essence, the authenticity and personal connection to one's Nen ability contribute significantly to its effectiveness and the user's overall proficiency in Nen.

After the boys mastered the basics they entered their second year under Snekk's mentorship. They were introduced to a series of advanced techniques that often combine and/or derive from the Four Major Principles. These techniques vastly expand the user's options in combat, but they also consume more aura than the Four Major Principles.

Gyo ("Focus") represents an advanced utilization of Ren, where a Nen user directs an augmented portion of their aura to a specific body part. This intensifies the strength of the chosen body part but leaves the rest of the body more susceptible.

Commonly applied to the eyes, Gyo enables a Nen user to perceive aura and Nen constructs concealed with In, as well as detect faint traces of aura that might otherwise go unnoticed.

An alternative iteration of Gyo involves gathering only the aura naturally seeping from the body, as opposed to the larger amount generated by Ren. While this variant still enhances the aura concentration in a chosen body part, resulting in increased power, the overall output is notably lower compared to the regular technique.

In ("Conceal") stands as an advanced manifestation of Zetsu, employed to make one's aura completely imperceptible, even to other Nen users. Unlike Zetsu, however, In doesn't halt the flow of the user's aura; instead, it conceals it, making it impossible to detect through any of the five senses or extrasensory perception. Consequently, this technique proves ideal for launching surprise attacks or setting traps, as it not only hides the user's presence but also conceals Nen constructs generated through Transmutation or Conjuration.

In can be countered by employing Gyo in the eyes or by utilizing Zetsu. When In conceals a portion (or even the entirety) of the user's aura output, seasoned Nen users may discern that their opponent is using this technique if minimal or no aura can be sensed, especially in situations that typically demand its presence, such as during combat.

En ("Circle") represents an advanced fusion of Ten and Ren techniques. While Ren typically envelops only a limited space around the user's body, En involves extending Ren over a broader area, simultaneously employing Ten to contain and give shape to the expanded aura, often forming a sphere. Users of En gain the ability to sense the shape and movements of anything within the aura-covered space, with precision and awareness levels contingent on their skill proficiency.

Notably, individuals using En emit a stronger reaction to Nen users compared to regular individuals, allowing for their differentiation. However, the drawback to this technique lies in its considerable strain on the Nen user, as the continuous expenditure of a substantial amount of aura proves exceedingly fatiguing. 

For En to be deemed a successful application, the Nen user must extend their aura to a radius surpassing two meters (6.56168 feet) and sustain it for a duration exceeding one minute. Proficient practitioners of En can often elevate their mastery to the extent of extending it in the form of a circle with a radius of 50 meters (54 yards, 2 feet, 0.5052 inches).

Ko ("Temper") is a composite technique involving the integration of Ten, Zetsu, Ren, Hatsu, and Gyo, wherein the entirety of the user's aura is focused into a specific body part. Gyo directs aura to a targeted body area, while Ten prevents its dissipation. Zetsu halts the aura flow in all other body parts, amplifying the output in the desired region. Ren further increases the volume of aura, endowing that particular body part with remarkable offensive potency and defensive resilience. Ko, on its own, is a formidable technique, but its effectiveness is heightened when complemented by the user's speed and strength, potentially resulting in an exponential power increase.

The trade-off, however, lies in leaving the rest of the user's body entirely vulnerable. When one Nen user utilizes Ko offensively and another defensively unless there's a significant strength discrepancy, the defensive Ko can likely fend off the offensive Ko. Nevertheless, any part of the defender's body not shielded by Ko remains exposed and susceptible to destruction. Due to its inherent risks, Ko is generally considered a predominantly offensive technique.

An incomplete iteration of Ko can be employed without Ren, especially during the learning phases to master the preceding steps before concentrating and containing an increased amount of aura. Some Nen users, particularly Enhancers, customize Ko into a Nen ability by attaching specific conditions to its application.

Ken ("Fortify") represents an advanced iteration of the fundamental Ten and Ren techniques, primarily serving a defensive purpose. In this technique, a Nen user maintains a state of Ren for an extended duration. The amount of aura enveloping the user's body during Ken is approximately 10 times greater than that in Ten.

Through Ken, a Nen user can defend against attacks originating from any direction, creating a robust protective barrier. However, the considerable amount of aura generated makes it physically taxing to sustain. Despite not matching the localized power of Ko on specific body parts, Ken is considered an effective defense against Ko, as it evenly safeguards the entire body.

Ken is often employed when cautiousness is required and is particularly useful when not immediately threatened by a Ko attack. Some Nen users choose to expand the radius of Ken to detect incoming attacks they might not visually perceive, resembling a miniature En in function. Occasionally, Ken is informally referred to as Ren due to the similarities between the two techniques.

Ryu ("Flow") is a term used to describe the application of Gyo while in a state of Ken, facilitating real-time adjustments in offensive and defensive values. Unlike Ko, which allocates 100% of one's aura either to offense or defense, and Ken, which evenly distributes it for balanced protection, Ryu involves redistributing one's aura according to specific percentages. For instance, one might focus 70% of their aura in one fist while distributing the remaining 30% across the rest of the body during an offensive strike. Alternatively, during a defensive move, an individual might allocate 80% of their aura to a specific leg, leaving 20% for the rest of the body to block an incoming kick. Ryu allows for inflicting damage on a Ken user without leaving oneself as exposed as during Ko, albeit at a lower power level.

Mastering Ryu proves challenging as it demands precise control over one's aura flow and the ability to estimate the opponent's aura utilization at a glance. Even if executed correctly, the movements of the aura flow carry the risk of telegraphing the user's next move if they are too slow.

The duo manages to get the basics of each down within six months, Snekk is impressed with them and happy about the money they help him rake in. Decided to teach them about the aura types and help them to figure out theirs.

There are six distinct types of aura: Enhancement, Transmutation, Emission, Conjuration, Manipulation, and Specialization. Each individual is inherently born with one of these six different aura types. Once a student of Nen discovers their own aura type, they can embark on the journey of learning how to apply the technique in a manner that aligns with their personality. This personalized approach can evolve into a unique and individual skill within the realm of Nen abilities.

The most widely recognized method (and the sole reliable technique depicted in the series) for determining one's aura type is through Water Divination (水みず見み式しき, Mizumishiki). In this divination practice, individuals float a leaf on the surface of a glass of water. To ascertain their aura type, a Nen student places their hands around the glass and performs Ren (or concentrates a greater-than-normal amount of aura in their hands, such as through Gyo). The resulting effect from their aura interacting with the glass reveals their specific aura type.

The outcomes are as follows:

- If the volume of the water changes, the user is classified as an Enhancer.

- If the taste of the water changes, the user falls under the category of a Transmuter.

- If the color of the water changes, the user is identified as an Emitter.

- If impurities manifest in the water, the user belongs to the Conjurer category.

- If the leaf moves on the water's surface, the user is labeled as a Manipulator.

- If a completely distinct change occurs, the user is categorized as a Specialist.

Feitan was a Transmuter and Valeer was a Specialist. During the remaining six months both of them work on mastering the advanced techniques and developing a Hatsu.

When the remaining six months were up they travelled together for a month before splitting up. Feitan wanted to try his hand at becoming an assassin and Valeer wanted to head to Heavens Arena. Both for the same reason to find suitable grindstones.

"Don't forget we meet Chrollo at the old hideout in eleven months"

"Yeah, yeah now piss off and take care of your murder Bonner"

"Tch you got some mouth for a 10-year-old"

"Uhuh"

They both stared at each other before chuckling. The duo bumped fists before heading their separate ways.