[Theory]Dojutsu increases physical prowess

[LUMOS ULTIMATUM]

Ever since sasuke's eyes changed from ms to ems, whenever he used chakra consuming techniques such as amaterasu or susanoo, he do not get exhaused anymore. His chakra levels have been upgraded when he got ems and they are proven by the fact he is still on his feet on the battlefield after using amaterasu and susanoo level 2-3 continuously without rest.

Furthermore, Madara's power was lower when he was fighting hashirama than he currently is. Ever since he awakened the rinnegan, it seems that he has become more powerful and have more chakra to the point he was able to survive against tailed beasts, use powerful techniques with minimal chakra loss(Limbo hengoku) and knock out several bijuus.

Not let's see nagato. He was indeed an uzumaki but his parents got killed rather easily. His chakra levels were monstrous even for an uzumaki. He was able to manipulate several paths with chakra itself for a long time and use their techniques. This in itself is extremely chakra consuming because all the chakra for the techniques is being deducted from one user. + he was able to use chibaku tensei, chou shinra tensei and rinne tensei to the point he used the eye to an extent similar to an uchiha clan member. Does the rinnegan account for this monstrous chakra levels as though he was a jinchuriki? Even Karin, an uzumaki does not have this much.

So, it could be that the eye is linked to the body and the body is linked to the eye. Proof? Kakashi's chakra was drained easier when he was using kamui at first but after long usage, his kamui became more powerful.
Explanations? It isnt that the kamui is taking less chakra. Obviously, if kamui is enhanced and become more powerful, it should take more chakra. So, it's kakashi's chakra levels and occular prowess that has been enhanced. Same goes for sasuke. At first, he could only use a level 1 susanoo when fighting kages and got drained. But after long usage, he was able to use level 2 susanoo and then get drained when fighting danzo.

So the eye responds with the body and the body with the eye.

Thoughts because I may be wrong.

 

[slaton02]

Not exactly, the only time I recall MS tech being a chakra problem was when Itachi was using them and we all know he has little chakra and had a sickness. When Sasuke had MS he never ran out of chakra because he used enton alot over amaterasu, Ems cancels the bad effects the MS caused the user and the others had Senju Dna or known chakra powerhouses. Kakashi's limit was 3 Kamuis and that was when he first started he wasn't used to it. It's like working out, it's gonna hurt till you get used to it and you can go longer over time. Kakashi has also been healed multiple times in this war and has had kyuubi chakra I believe he used 4 kamuis before collapsing. So if had to vote if Dojutsu increase chakra, I say no but physical prowess? to a small degree.

 

[The Necromancer]

I'm not so sure. I think the "boost" we see with the awakening of the EMS is really just the user adjusting to the jutsu, and learning how to conserve chakra while performing it. In the same way Kakashi was able to increase the number of Raikiri and Kamui he can fire off in a battle, an EMS user can actually train to use their EMS in battle more efficiently, a trait that was near impossible with the MS, as it would cause blindness before the user could ever become proficient in it.

 

[CJ Mac]

I don't think so. The problems that everybody had before when using their doujutsu were all caused by over-exertion. When Sasuke first got his MS, using Amaterasu would make his eyes bleed. I don't even remember if his eyes bled while fighting Danzo, but I'm sure it probably took a couple uses of his eyes. The fact that he doesn't have the problems so early on is merely because his body is more used to the higher level doujutsu. In fact, I think Sasuke's eyes bled a little in a recent chapter, while fighting Obito.

Kakashi used to have the same problem after just using his Sharingan for basic tracking and fighting. After fighting Zabuza, he was laid up in a hospital bed for a week, and that didn't even involve using any Doujutsu. During his fight with Deidara, Kakashi used Kamui once and was in a similar predicament. Against Pain, I think he used it a couple times, and died due to chakra loss. During the war, though, he has used his Sharingan almost the entire time to some extent. Using it for its visual prowess no longer exhausts him, and he can use his Kamui half a dozen times before getting tired. Even then, he is able to recover from using Kamui enough to use it again after a little while. This has nothing to do with his eyes, but rather is just his body getting used to his Sharingan.

Madara is more powerful because he now has Hashirama's Sage Mode. Plus, he has his full Rinnegan. They hinted during the last chapter that the Edo version of the Rinnegan might not be as powerful as the actual eye. This hasn't been confirmed, but it might have been Kishi's way of quickly explaining the increase in power. That said, Madara did use his Edo Rinnegan to drop two meteors on the Alliance, and I don't think he's going to do that again, now that he is alive (at least while he still has a chance of winning).

 

[AlphaScythian]

Maybe body adapts to the eye over time? The eye puts enormous stress to the body, its basically a work out for it in long run.
Looks like uchiha dont even need to train their bodies once they get powerful eyes XD