Naruto 689 – Read Naruto 689 Spoilers
But we know Itachi actually had access to Susanoo Naruto 689 before that time when he used it on his death bed against Sasuke, so him using it while nearly dead is just a matter of using something he was already proficient with with the little bit of chakra he still had left. That’s not what Kakashi did.
He used a technique neither he nor Obito had managed to fully manifest or had experience with. I agree that Kishimoto will just throw what he wants into the manga at any given time though.People seem to be forgetting this is the same manga where Itachi transferred all his MS techs to Sasuke by touching his forehead….
The whole thing seems pretty simple to me; Obito was a ten tails Jin, he has an understanding of way life AND death are bound together through chakra that most characters don’t have.
He bonded what was left of his chakra in the material world to Kakashi directly. He didn’t just give him eyes, he gave him everything he could. The chakra boost won’t last. But the knowledge will, and the eyes will until they go blind (although with the amount of Hashirama DNA floating around not sure that’s necessary either).
when the extra chakra boost wears off he now has Sakura as a human battery. That and saying “Naruto!!” in shock are her basic functions in life because Kishi has a disdain for women that must stem from some pretty heavy childhood ridicule.