From what I've heard around, it seems to be by sending a chakra signal to affect their chakra system. As the opponent's chakra is disturbed, it affects his ability to perceive, and makes him see illusions, that they perceive as reality. What I do is to visualise what I want the opponent to perceive, and then send a chakra signal to their body, containing the information I just visualized. Sending the signal can be done by eye contact, sound or even other means like hand seals.Hm. Decent enough. Remember that the only limit any Genjutsu user has is their imagination.
Well then, how would you know how to inflict someone with Genjutsu then?
Α) I can stab myself to the hand or knee, or bite my lip. I think anything will work, as long as it's not fatal...A. Excellent, but what specific parts?
B. Ah, Nagashi works just as well.
C. What type of people can insert chakra into your body? What about jinchuurikis?
D. Excellent.
Hmmm... For example, I could change the environment into a great fire all around. The opponent would use a water jutsu to defend, so I could quickly use a raiton to toast them.How about getting him to react a certain way?
Try to change the environment to something where I would use an elemental jutsu to counter it, then you counter my counter.
I send chakra to the clone, and program it to make him see me dissolving into sakura petals. The, the (imaginary) petals start flying towards him, surround him and block his vision. This jutsu is very useful to conseal my movements, as the opponent won't see me anymore. Then, the opponent will only see chary blossoms, so he won't see any incoming jutsu, and will be unable to defend against them.Excellent job.
Now, proceed to take over my clone's five senses once more and have him believe that you have dissolved into many cherry blossom petals. Have those very petals surround him, blocking his vision and tell me why this is significant.( Magen: Kokoni Arazu no Jutsu ) - Demonic Illusion: False Surroundings Technique
Rank: D
Type: Supplementary
Range: Short-Mid
Chakra Cost: 10 (+5 if you use it double)
Damage Points: N/A
Description: The user casts an illusion over an area that allows him to manipulate the way an area looks to fool an opponent. He can only change the way the terrain looks, and not any other feature.
he will also be unable to use aimed jutsu at me, and will have to relay to wide range jutsu, that are much less focused, thus easyer to defend against...Good. So why else is knowing your enemy's field of vision important in battles?