Board Thread:Naruto Discussions/@comment-5303512-20151228183932/@comment-734582-20151229202945

Ravenlot 27 wrote: I think I should also add that Sharingan cannon give it's wielder the ability to use any elemental jutsu I don't think it does. Please remember that the initial idea of the Sharingan was revealed by Zabuza to be a lie: It doesn't copy abilities, Kakashi used Genjutsu to make people think he did. Combined with the ability to see chakra, even the smallest movements and reading Handsigns, a Sharingan wielder has all the ingredients to easily figure out jutsu.

Ravenlot 27 wrote: Also I think that Rinnegan, unlike Sharingan, doesn't give insight into the jutsu, it should be rather called a storehouse of all the techniques in the existence This is just pure speculation. Nagato seemed to read Narutos movements and abilties like a Sharingan user does. Rinnegan also is the superior Dojutsu of the Sharinan. The Rinnegan originated from Hagoromo, who had such good eyes that he was the only one to clearly see Naruto and Sasuke's Transmigrancy.The Rinnegan seems to add the ability to recognize the specific elemental release on top of everything the Sharingan does which means that to a Rinnegan user, no aspect of a jutsu is hidden.

Contrast this to a basic Ninja, who can't see chakra, can only see as well as a human can and can't "read" another's handsigns (Sasuke mentions vs Deidera that any handsign, no matter how fast, can be decoded by Sharingan) and so has to learn jutsu by getting the feel of an invisible force just right, unlike a Sharingan user who just sees how it works.