Physical Attributes:

Strength: People with high strength can lift more massive objects and inflict additional damage. They may also find their bodies lighter, which in turn allows lessening physical efforts. Stamina is tried only after this attribute is overused.

Fitness: The body's natural endowment but can progress with proper training. Fitness refers to resilience, stamina, resistance to tiredness, pain, tear, poison, damage, and sickness. People with elevated fitness can also undergo more strenuous activities, both mentally and physically.

Dexterity: The ability to wield limbs with precision, speed, and technique, as well as make delicate motions. In essence, it allows maximizing the potential of strength and perception.

Perception: Awareness, vision, smell, hearing, etc. Higher perception enhances sensorial abilities.

Mental Attributes:

Wisdom: The capacity to grasp abstract concepts, think, learn faster, and feel with more creativity. Wisdom likewise helps with spiritual or psychic tasks by lowering strain.

Charisma: The ability to entice or seduce strangers or leave a good impression naturally. When used along with aura, it can enhance hypnotic, hex, and coercion effects.

Versatility: The ability to adapt or be adapted to many different functions or activities. People with high versatility can pick up unfamiliar efforts, situations, or abilities quickly. Versatile people are less likely to experience hardships due to stress.

Composure: One of the crucial mental attributes for those with low versatility. People with high composure not only deal with stress better, relax faster, but they also use skills with more casualness and familiarity.

Nen chart and Concepts:

At Level 1:

Enhancement:

STR+5/FIT+5/DEX+1/PERC+1

Emission:

PERC+5/STR+5/DEX+1/CHA+1

Transmutation:

DEX+5/STR+5/PERC+1/WIS+1

Manipulation:

COMP+5/CHA+5/WIS+1/PERC+1

Conjuration:

WIS+5/CHA+5/VERS+1/DEX+1

Specialization:

CHA+5/VERS+5/COMP+1/WIS+1

Nen Categories:

(I simplified or added to the information from the Hunterpedia for this section since a lot of people have issues interpreting nen natures)

1/Enhancement:

The most balanced nen category and the one also considered the toughest. Enhancers, like the name implies, focus on enhancing parts of their bodies or the abilities of items. The enhancement isn't limited to physical matter, however. The main principle is to "magnify" or increase the beneficial/detrimental effects of something (Healing properties, etc.).

Affinities:

100% Enhancement

80% Transmutation, Emission

60% Manipulation, Conjuration

0% Specialization

2/Emission:

Remarkably similar to conjuration. Emitters can disconnect aura from their bodies and use it as projectiles or create an external ability (identical to conjurers) that is, although invisible to people without nen. That's the only real difference between emitters and conjurers. Conjurers invoke something everyone can see in the physical world, and they're not as masterful with projection skills. Propelling aura is something peculiar to emitters.

Affinities:

100% Emission

80% Manipulation, Enhancement

60%Transmutation

40% Conjuration

0% Specialization

3/Transmutation:

Transmutation is one, if not the most challenging category to understand.

Transmuters primarily change the natural properties of aura and objects. In some ways, it is similar to enhancement but also completely different. When enhancers simply increase the effects of the inherent properties, transmuters change those at their core (atomic level) to produce things such as fire, ice, or electricity.

This category is also sometimes mistaken as emission. Transmuters also project their aura to attack other people, but unlike emitters, they don't separate it from their bodies. (Zeno's dragon lance, Hisoka's bungee gum, Machi's threads).

Any transmuted (invisible to ordinary people) aura that detaches itself from the user is at least combined with emission. (Zeno's Dragon Dive, Morel's Deep purple)

Any transmuted aura (visible to ordinary people) that detaches itself from the user's body is at least combined with conjuration. (Hisoka's Texture surprise)

Lastly, it is entirely different from conjuration in the sense that the summoned aura (ice, fire, gum, electricity...) is invisible to regular people.

Affinities:

100% Transmutation

80% Conjuration, Enhancement

60% Emission

40% Manipulation

0% Specialization

4/Manipulation:

The antithesis of enhancement and probably the most challenging type to master. Manipulators don't reinforce things but simply tinker with objects, devices, aura, or anything for that matter. Unlike enhancers, they can do so remotely.

This remote aptitude to control and move things is why most manipulators will enjoy using emission concurrently with their type. The reason is that puppeteering other people or objects through aura is more comfortable.

The physical manipulation/mutation aspect is where things get complex:

Enhancers don't issue instructions; they simply bolster the metabolic of things.

Manipulators, though, can command the brain to release more adrenaline or testosterone, or force objects to move, etc. In a sense, most manipulators are puppeteers.

The main discrepancy between this category and the others is that it works with things that already exist; it doesn't generate anything new. (Example: Even if ribosomes are ordered to produce proteins, it leaves a negative effect somewhere else with no enrichment)

This category works best with enhancement, but it sadly is not its best affinity.

Affinities:

100% Manipulation

80% Emission

60% Enhancement, Conjuration

40% Transmutation

1% Specialization

5/Conjuration:

The most mysterious and obscure nen category, but in some ways also the most expendable. There isn't anything that emitters can't do that conjurers do. Emitters shoot aura better than them and manipulate it even better due to their closeness with manipulation.

Conjurers only have three specificities that make this nen category the second most sinister after specialization:

-Conjured creatures/people (Nen beasts) are visible to anybody without nen.

-Nen beasts live independently from the summoner (even after death)

-Summoned beasts can breed, thus produce offspring.

Just like manipulation, this category would work best with enhancement. Sadly it isn't its best affinity.

Affinities:

100% Conjuration

80% Transmutation

60% Enhancement, Manipulation

40% Emission

1% Specialization

6/Specialization:

The most cryptic and erratic category during fights. Specialization doesn't have a precise concept. Any nen user that cannot be stigmatized into one group due to the exotic nature of their skills is referred to as a specialist. Some specialists can steal other people's nen; others can see the future or predict deaths, etc.

There isn't a definite range of skills specialists can have, and most of the time, the environment in which they live influences their powers.

Affinities:

100% Specialization

80% Manipulation, Conjuration

60% Emission, Transmutation

40% Enhancement

Four Basic Nen Fundamentals

Ten:

This technique allows a Nen user to contain aura by enfolding their body with it. It is the most fundamental technique. Thanks to it, the body will be strengthened, and the aging process can also be slowed down.

Training benefits: +Fitness

Zetsu:

The stealth technique. It stops the flow of aura from the body. Best used in combat only when the user is confident in his natural defenses.

Training benefits: +Perception

Ren:

Involves training with and improve the aura formed by using Ten. It allows someone to produce and use unusual amounts of aura. Ren can be compared to a basic training exercise, which means it is essential for anyone who wants to gain power. Practicing Ren in specific environments can help in forming a Hatsu. It is especially true for transmuters.

Training benefits: +Strength/+Wisdom/+Charisma

Hatsu:

The technique of freely displaying the magical properties of the aura cultivated by Ren. It is also the last one of the four fundamental Nen techniques.

Hatsu allows nen users to convert body specificities and creative thoughts into battle skills or useful tools.

Training benefits: +Dexterity/+Versatility/+Charisma

Advanced Nen Applications

KO:

This technique makes uses of all four nen fundamentals. (Ten, Ren, Zetsu, Hatsu)

The person concentrates all the energy on one point of the body to perform a charged and explosive strike.

Sounds similar to Gyo, which only uses Ren, however.

Note: On a similar power and talent plane, Enhancers commonly pick up this skill faster than others

Training benefits: +Strength/+Dexterity

Ken:

A firm defensive technique whereby a Nen user maintains a state of Ren over their entire body. Compared to KO, which concentrates all the user's aura on a body part, the defensive power of Ken is weaker on any given part of the body, but it allows the user to defend from all directions. Hence, it is suitable to use when fighting against multiple opponents. However, one must be careful not to overuse it to avoid running out of aura.

Training benefits: +Dexterity

Shu

Application of Ten, which allows a Nen user to surround limbs or objects with aura. It primarily reinforces the lethal properties of the weapon or body part used.

If people use Shu on a sword or a bullet, it will turn sharper and harder.

If used on a gun, it will become more compact and increase the discharge force.

If used on a bullet, it will gain more resistance and dynamism.

Note: On a similar power and talent plane, Enhancers commonly pick up this skill faster than others.

Training benefits: +Strength/+Fitness

En:

The user expands aura in the surroundings for detection purposes. They will then be able to feel the shape and movements of people within the range of their En.

Training benefits: +Perception

Ryu:

The technique of instantly switching between Ken and KO. It allows the user to concentrate aura or disperse aura promptly, making their offense and defense more dynamic. To use the proper amount of aura at the right times, one must also use their intellect.

Training benefits: +Dexterity/+Wisdom/+Versatility/+Composure

In:

It is an upper-level application of Zetsu that can hide a Nen user's aura almost wholly. This technique is especially useful to surprise the opponent and perform sneak attacks with weapons/items.

Training benefits: +Dexterity

Gyo:

One of the paramount advanced fundamentals. It is the technique any beginner needs to learn before engaging in life or death nen battles. The user concentrates his Ren in the eyes to see the invisible aura or enhance his vision. Useful to spy on opponents.

Gyo can be used to defend against attacks, according to Bisky, however. (Guess KO leaves you more defenseless elsewhere due to its insane charge requirements)

Training benefits: +Perception

Complex Nen Conditions:

Covenants, Vows, and restrictions

Restrictions: Conditions placed to make a skill more potent and easier to use. Those conditions need to respect each nen nature principles for the ability to be simple to use. Nen users can purposefully convolute those stipulations to strengthen a skill. Examples: Enhancers should fight in close combat Emitters should avoid close combat etc. Vows: The user decides on a punishment if he breaks one of the restrictions imposed. The harder the sentence, the stronger the aura. Covenants: Dangerous agreements composed by the user. Those conditions are dealt either with his conscience/soul, or some spiritual entity. The user borrows aura from his lifeforce, dormant potential, or unconventional being, in exchange for something. To resume: 1/Restrictions are merely simple requirements to boost an ability 2/Vows serve as punishment for breaking restrictions 3/Covenants are sinister contracts someone uses to borrow power.