Board Thread:Theories and Speculation/@comment-734582-20150720112958/@comment-734582-20150723131709

GreatestSin wrote: a simple jutsu doesnt equal to a easy one... rasengan is simple jutsu too, roation and mentaining the chakra in a stable form, but it isnt easy either... Like i said: Kabuto could use hundreds of Edo Tensei without problem. If it had any of the properties you mentioned, even one Edo Tensei would be an immense feat. Yet Kabuto casually explains it to Madara while already having made hundreds of Edo Tensei, showing that there's neither a whole lot to the Jutsu, nor doesn't seem to require a lot of chakra as it doesn't tire him out even the least.

then lets say it works, lets say it is possible to come over to the living world despite the fact that obito was down chakra wise... it still doesnt make space-time-jutsu into a "posses someone"-jutsu... It's not. Considering the chain of events, it's likely that he could simply possess Kakashi in a limited matter (unlike Edo Tensei).

I want to point out that Obito says "our chakras have the power to connect both worlds" but i'm so far unsure how to interpret it. Kakashi did have Obito's chakra for over a decade in the form of having his eye, and Kakashi did die and come back to life. The biggest question left open is a question of uniqueness: Is what Obito did, possible only between them for the aforementioned reasons, or is it a power that any kamui user has (but because we've only seen one person awaken kamui we don't know).

Lastly, i think it might be better to rephrase my original deduction so hopefully the chain of logic is clearer.

For Obito to possess Kakashi, three things need to be proven:
 * The afterlife is an actual dimension
 * Kamui can connect to dimensions other than the main and the pocket dimension
 * That possession grants powers for as long as the possession goes on.

Edo tensei neatly takes care of one and three:


 * Edo Tensei is labelled as a Summoning Jutsu, which is a space-time jutsu, just like Kamui. Hence, if summoning can reach the afterlife, so can Kamui.
 * Kamui can synchronize with any dimension as long as it has access to that dimension. E.g. by synchronizing with Kaguya's dimensional gate he could reach her other dimension. Once in that dimension his pocket dimension was an easy jump away, and the Afterlife was also an easy jump away.
 * Edo Tensei involves the user taking DNA, using this to contract the persons soul, and using a living body as an anchor for the to-be-summoned soul. For as long as Edo Tensei persists, the anchor body takes on the power of the possessing soul. So, Kakashi's temporary Sharingan can exist under the rules of Edo Tensei.

Ergo, what Obito did is neither a deus ex machina (all it's components are introduced prior), nor a plot hole, and so your main argument has been proven wrong.

Your statement that it would require immense chakra is baseless, just as the fact that his chakra is low. Just because traversing dimensions costs a lot of chakra, does not mean he's dry. Even if he doesn't have the chakra to make another inter-dimensional jump between Kaguya dimensions, does not mean he doesn't have the chakra to jump between his own and the real world, or the afterlife for that matter.

Lastly, Obito could perform Kamui moments before his death, and did not die from lack of chakra. He also spammed Kamui throughout his life without affecting him in any way. If a kid with a True, double Sharingan can spam it's power without effort, yet someone with a transplanted Sharingan goes down after using its power a bit, that just shows how much a Sharingans power changes with a user. If Kakashi can use it a couple of times, that means Obito can use it dozens to hundreds of times (since it doesn't even tire him a bit). Ergo, regular dimension jumping is not an energy-intensive process. Even so, the aimed version seemed to use more chakra than Obito's personal Kamui.