Byakugan, Sharingan, and Genjutsu

[MortisMage]

I came here looking to research the Byakugan (and what better community for Hyuuga-related ideas is there?). I'm actually trying to figure out how the Sharingan and Byakugan respond to genjutsu so that I can improve a scene inside of my own fan fic.

See, the Sharingan notices details, while the Byakugan sees through things (and if you like the anime, acts like a magnifying lens). So, Sasuke would detect an illusion, perhaps, by noticing that tall grass is actually short glass, as he might notice the genjutsu flickering in places. While Neji might notice, via X-Ray, that part of the grass is transparent.

However, while Sasuke can see the color of chakra, Neji can't see through Shadow Clones with even amounts - however, he does pick up on the real Naruto taking cover. So to me, Sasuke has the more "notice an immediate effect" whereas Neji might notice a physical discrepancy.

There are scenes of the Sharingan breaking genjutsu that I can work off of, but there aren't nearly as many examples of the Byakugan breaking genjutsu.

For instance; I'd be interested to know what would happen if Ino used her Mind Transfer jutsu on Neji or Hinata from behind (giggity), without them being aware.

Would they detect the jutsu and call her on it, aware that she tried to mindjack them? There's evidence that Sakura was not conscious of Ino's attempts until the preliminary round of the Chunin Exams. However, Obito dispelled Ino's control, likely due to having a Sharingan.

So, in short: How does the Byakugan respond/detect to genjutsu/control techniques?

Rather than make another thread, I'll roll this question in here too:

Can the Sharingan copy the Gentle Fist?

Some would say yes, as I would, since it copied Rock Lee's style. However, I believe the disadvantages demonstrated with Sasuke copying Lee's style would similarly apply to Neji's as well. There was a discussion I read recently about the vectoring involved, and while I barely made heads or tails of it, I can see how copying an instance of Neji or Hinata would prove disasterous, were a Sharingan user to opt for Gentle Fist during a fight.

Or in short, while I think he could copy some of the movements, would Sasuke be able to duplicate the Gentle Fist effectively, or would it suffer from his body's lack of training similar to how it did with Rock Lee's techniques?

[MrRigger2]

So, in short: How does the Byakugan respond/detect to genjutsu/control techniques?

Well, as you outlined, there's not very many examples in canon, and Kishimoto isn't necessarily the most consistent author out there when it comes to the details of how things work, so most theories are just educated guesses.

Seeing through genjutsu would probably work as you described. They would either see it as ethereal versions of the genjutsu or just not perceive the genjutsu at all. However, as it is an eye-based technique, I'd say the Byakyugan (and the Sharingan) could only see through visual based genjutsu, not an auditory or olfactory genjutsu.

Regarding mind control techniques like the Yamanaka Clan techniques, I don't think the Byakyugan would give them any special defenses. The Mind Body Switch Technique and other techniques derived from them are all ninjutsu, not genjutsu. The Hyuuga may be able to better predict the techniques due to their ability to see chakra, but other than that, they wouldn't have any special way to avoid or throw off the techniques, at least none granted by their bloodline.

Can the Sharingan copy the Gentle Fist?

Or in short, while I think he could copy some of the movements, would Sasuke be able to duplicate the Gentle Fist effectively, or would it suffer from his body's lack of training similar to how it did with Rock Lee's techniques?

Can it copy the physical movements of the Gentle Fist? Absolutely. There doesn't seem to be any special movements that a normal ninja couldn't duplicate. Sasuke might have to do some flexibility/speed training, but other than that, he could copy the physical movements easily.

However, the point of the Gentle Fist isn't the movements, it's the ability to block tenketsu. Sasuke may be able to express chakra through his fingers the way Neji and Hinata do, but that doesn't mean he can see the targets. Given that people don't just study the body and figure out where tenketsu are normally, that means there's something more going on. Tenketsu might be slightly displaced in every person, but more likely, the tenketsu are so small and the strike has to be so precise that if you aren't able to see it, you wouldn't be able to block the tenketsu reliably.

In conclusion, Sasuke could copy the Gentle Fist and use its movements, however, he wouldn't be able to block the chakra of his opponents the way Neji does, as Sasuke doesn't have the Byakyugan.

MrRigger

[jgkitarel]

Can it copy the physical movements of the Gentle Fist? Absolutely. There doesn't seem to be any special movements that a normal ninja couldn't duplicate. Sasuke might have to do some flexibility/speed training, but other than that, he could copy the physical movements easily.

However, the point of the Gentle Fist isn't the movements, it's the ability to block tenketsu. Sasuke may be able to express chakra through his fingers the way Neji and Hinata do, but that doesn't mean he can see the targets. Given that people don't just study the body and figure out where tenketsu are normally, that means there's something more going on. Tenketsu might be slightly displaced in every person, but more likely, the tenketsu are so small and the strike has to be so precise that if you aren't able to see it, you wouldn't be able to block the tenketsu reliably.

In conclusion, Sasuke could copy the Gentle Fist and use its movements, however, he wouldn't be able to block the chakra of his opponents the way Neji does, as Sasuke doesn't have the Byakyugan.

MrRigger

I don't entirely agree with Sasuke not being able to fully copy the style and it's abilities. The problem would not be in his ability to fully copy the style and it's ability to block tenketsu, but in the training necessary to ensure the you would hit them and have the precise control, both of your body and chakra, in order to do so reliably. The Byakugan is an extremely effective aid in seeing them, so you can easily adjust to it, but even with that, the Hyuuga require extensive training in order to use their style effectively. It's not a matter of it being impossible, but requiring such specialized training that those without the dojutsu to give them an assist would consider the effort required too prohibitive to warrant it when they could better use their time to train in other skills which they could effectively use.

[doc.exe]

For instance; I'd be interested to know what would happen if Ino used her Mind Transfer jutsu on Neji or Hinata from behind (giggity), without them being aware.

Would they detect the jutsu and call her on it, aware that she tried to mindjack them? There's evidence that Sakura was not conscious of Ino's attempts until the preliminary round of the Chunin Exams. However, Obito dispelled Ino's control, likely due to having a Sharingan.

I’m not sure if that was really due to the Sharingan, he “interfacing” with the Juubi or pure mental fortitude. That last one (mental fortitude) might probably be more related to whether or not you can detect and break free from a mind control technique, as Sakura was capable of breaking free from Ino’s Shintenshin due to her “inner” personality, and Kisame managed to repel Aoba when he was invading his mind, apparently by sheer will alone (he bit his tongue despite being semi-unconcious, forcing himself to "awaken").

I'd say the Byakyugan (and the Sharingan) could only see through visual based genjutsu, not an auditory or olfactory genjutsu.

This part is actually supported in canon. The Sharingan, Byakugan and Rin’negan can see chakra sources (although in the Rin’negan case, it has never been effectively explained how its capabilities compare to the other doujutsu on this area) and apparently have some capabilities to dispel or see through visual genjutsu. But the Sharingan and Rin’negan have been shown to be vulnerable to auditory genjutsu, and I doubt the Byakugan would fare better against it. Indeed, this might actually be the major weak point of doujutsu.

Pain was captured by the Magen Gama Rinsho (aka, the Frog Song Genjutsu) of Jiraiya and would have been defeated if not for his spare bodies. Itachi and Sasuke were trapped by Kabuto emulating Tayuya’s demonic flute genjutsu and required to use the Mangekyo Sharingan on each other in order to break free.

[jgkitarel]

Auditory and olfactory genjutsu are extremely dangerous for that reason. They are also harder to pull off, since the genjutsu user suffers from the same sensory weakness that a normal person does. Heavy reliance on sight, which means visual genjutsu are "easier" to pull off. Of course, I can see one real big use for olfactory genjutsu. Covering up the scents of some extremely potent toxins in an area. Auditory genjutsu can be used to play hell with a persons balance in ways that visual couldn't (not to mention fool them as to where an attack is coming from).

We also shouldn't forget what a genjutsu which is capable of sensory deprivation can do.