>>5799775“It’s not all doom and gloom, Otomo. Frankly speaking, a channel has been opened between you and the afterlife. That’s all it is. The nature of the channel existing at all means your life force is disappearing at a slow trickle, and being replaced by your sister’s own spiritual energy… The nature of which I doubt there is a shinobi alive who could accurately explain to you. However, speaking as the Hokage who has studied a somewhat similar jutsu developed by Tobirama and the Uzumaki clan: The only reason the jutsu ‘failed’ is because whatever will your sister had that still exists within this energy does not want to harm you. The transfer is slow, and there is no need for it to be slow. If her soul, wherever it is, truly wanted your body… You would have been wholly replaced within seconds of the completion of the jutsu. Since this isn’t the case, your chances of survival are quite high, as her spirit clearly means you no harm. Piece by piece you your soul will fade into the afterlifel, and you will gain new pieces from her… But in small enough portions at a time that they’re being naturalized as part of you, and vice versa. If the process ever does complete you likely won’t realize a difference at all… Like a ship being replaced one plank of wood a week over the course of ten years would still be the same ship with no discernable trace that there’s nothing left of the original after it’s over… Except in this case, your chakra signature will have an otherworldly character to it forever. You’ll likely find that spirits consider you halfway between life and death, and your jutsu will inherently be more effective against the incorporeal. You may even find yourself able to pass through barriers that keep all living things out, though the specific ramifications are hard to pin down…”
Another long puff on his pipe. “As for a cure? Most likely impossible. The jutsu is no longer ongoing, it opened a channel between you and your sister in the afterlife and then it ended. That channel is now part of the nature of your spirit, not the byproduct of an ongoing effect that can be canceled. Though it’s likely a cure isn't needed, insofar as your sister’s spirit doesn’t decide to hurt you after all. Which I doubt will ever happen. I said it ‘could’ prove fatal only because a more selfish individual being summoned from the other side could take advantage of it to kill you and live again, but… You’ve likely been living with this channel open since you were a toddler, and your sister’s spirit has never ousted yours. I don’t see any reason it ever would. Now, as for other ways the exchange between the two of you could be increased? If you died, or nearly died, the channel would open wider. If you died it would be a moot point, but only nearly? I don’t know what would happen. It could accelerate your demise, or it could save your life by opening a stable bridge between life and death.”
