Genjutsu is one of the main jutsu categories which uses chakra. Unlike ninjutsu, the effects of Genjutsu are not real, being only illusions experienced by those who fall victim to it. Genjutsu is created when a ninja controls the chakra flow of a target's cerebral nervous system, thereby affecting their five senses. This is frequently used to create false images and/or trick the body into believing its has experienced physical pain. Genjutsu can also be used to manipulate others - similar to brainwashing - by feeding the victim illusive suggestions.
Having the Genjutsu Jutsu Style allows you to preform these Rank D techniques without purchasing jutsu.
Physic Attack: With an established trigger you can use Genjutsu to cause mental stress.
Create Illusions: Can use Genjutsu to create illusions that affect targets.
Create Doubt: Create invasive thoughts that could overcome aspects of confidence and structure.
Illusionary Defense: Can use Genjutsu to defend as long as the target has tagged Genjutsu Aspects.
GENJUTSU STYLES
Sight
One of the easier senses to initiate genjutsu with, sight is used by channeling the chakra through the user, through another person, or through an object, to instigate the genjutsu. Common examples of this are eye contact, seeing the hand seals, seeing a specific weapon, or seeing an action. The intend target(s) must place their eyes on the initiator for at least a brief moment to be initiated.
Its understood that typically, the harder it is to get someone to look at something, the stronger the genjutsu is. This means that while “seeing the user perform the hand seals” is typically pretty easy to obtain “maintaining eye contact with the user” is much harder to retain, so the latter is likely a much stronger genjutsu, allowing for more strength the longer the eye contact is maintained.
Hearing
Arguably the easiest sense to use to initiate genjutsu with, hearing is used by channeling chakra through a sound. This can be a sound made by the user, made by a weapon, or made by an ally. Common examples of this are the sound of clapping, whistling, a bell attached to a weapon, or even the sound of an exploding tag going off. The intended target(s) must hear the sound for at least a brief moment to be initiated.
Its understood that typically, the longer a sound lasts, the stronger the genjutsu is. The strongest sound based genjutsu typically require the user to maintain a continuous sound (typically playing some sort of instrument), that preoccupies them to some length. That being said “hearing the user clap their hands” is likely a weaker jutsu than jutsu that require ‘as long as the user continues talking’.
Using sound based genjutsu is the most commonplace genjutsu initiator found.
Touch
One of the more difficult genjutsu initiators to use, touch based genjutsu are initiated through physical sensation. This can be done by the user touching the intended target, striking them with a weapon, or even them holding an object. Common examples would be the user touching the targets forehead, slicing them with a kunai, or having them pick up a letter. The intended target does not have to feel the sensation, as long as it’s there (in the case of characters that may be paralyzed or have some other effect going on).
It is understood that typically, the harder it is to pull off contact, the stronger the genjutsu is. This is why touch can be one of the hardest initiators to specialize in, as in the middle of a fighting, grabbing a hold of someone may not be easy for a genjutsu user who is not usually in the middle of a fight. Just grazing a target wherever is a lot easier, and typically a weaker genjutsu, than having to grab hold of a specific body part for a length of time. Sustained contact can also allow for stronger genjutsu.
Using touch based genjutsu is rare for combat based shinobi, but many interrogators enjoy utilizing them.
Taste
Arguably the most difficult initiator to use, taste based genjutsu are initiated through having the user physically taste something. This can really only be done one way, by introducing some object or liquid into the mouth. An example would be hitting them with a body of water, and getting that water in the mouth, or shoving a pill into their mouth, or even simply handing them a plate of food and having them eat.
It is understood that the harder it would be to get the initiator into the targets mouth, the stronger the genjutsu is. Taste based genjutsu are considered some of the strongest genjutsu, purely because they can be so hard to pull off. Typically, the genjutsu that require larger amounts of food are stronger than ones that require just a small amount of liquid to be tasted.
Using taste based genjutsu is extremely rare, but finds its use for users specializing in espionage.
Smell
A somewhat common initiator to use, smell finds itself in an unique niche between difficult to apply, and difficult to avoid. Genjutsu using smell are initiated through the user evoking a scent from themselves, or through some sort of medium. Most commonplace are the smell of the users breath, the scent of flowers, or the smell of salt.
It is understood that the harder it is to produce the scent, the stronger the genjutsu is. This means genjutsu initiated from the scent coming from a field of flowers are typically weaker than perhaps the scent of a perfume the user is wearing. Scent based genjutsu can be very hard to avoid, as typically the targets are not even aware they are smelling the scent.
Using scent based genjutsu isn’t common, but it isn’t a rare occurrence either, filling a very specific niche for users who find it useful.
Overcoming Genjutsu
-A victim's chakra flow, if disrupted enough, can break the caster's influence. Can be done by the victim themselves, or an ally who emits chakra into them. (Mind Overcome vs Genjutsu Skill of the Caster)
-Receiving physical stress equal to the casters Genjutsu Skill level + Shinobi Rank.