"What's this?"
"The result of my efforts over the last three months," I replied.
"This is..." Mito said in surprise, unfolding the scroll and examining the seal.
"A combination of Infuin and Iyaku Fuin," I nodded.
"But why..."
"This seal will allow you to live longer than just a few miserable months after the fox's extraction."
"Where did you get this?" Mito's suddenly heavier gaze made me squirm a bit, but I met it head-on.
"From Grandpa, and I've read about biju before," I answered, "considering Kushina's presence here, it's not hard to guess the reason, especially with almost identical chakra."
"And the seal...?"
"...should provide some stability to your keirakukei after resealing and ideally allow our kekkei genkai to give you at least a few more years of life without the adverse effects of the biju's toxic chakra."
"Hmm, it seems like you've made the seal without any obvious mistakes," Mito tapped her finger on her lips thoughtfully, "how confident are you in the outcome?"
"I'm a hundred percent confident in the positive result, but as for how much additional time can be gained in recovery, I have no idea," I honestly replied, "no one has studied the properties of our kekkei genkai for understandable reasons, and it's especially difficult to say anything concrete in the case of jinchuriki."
"Considering that I'm the first jinchuriki of the Nine-Tails, especially among the clan, it's not surprising," Mito shook her head.
After thinking about it for a while, I asked a quite logical question — why isn't the Slug Princess doing anything? Together, they could come up with something better than my crude contraption.
"Have you been examined by Tsunade or discussed this with her?"
"Why? Uzumakis hardly ever get sick, and even wounds on us heal quickly, so I've never been in the hospital," the elderly kunoichi shrugged, "besides, no Uzumaki would want to become a test subject, and it's not worth revealing the potential of our kekkei genkai to outsiders, even allies. My granddaughter is Sarutobi's student."
"So Tsunade hasn't tried to extend your life after extracting the Nine-Tails, considering your age suitable for death from old age," I nodded.
"Exactly! Given the exacerbated relations between Konoha and Uzushiogakure over the past four years, it just wasn't a priority," the relative said sadly, "and I've come to terms with it."
During our conversation, which started near the window where I watched the departing clone with Kushina, we moved to the living room and settled comfortably in soft armchairs, next to which were round tables with vases of cookies, specifically for such occasions. After crunching on some cookies, I continued the conversation.
"And it's a shame! Over time, I conducted a series of experiments with our chakra on various living creatures as well as on my own flesh," cutting pieces of meat from myself was very painful and scary, but one does what one must for science, "and discovered some peculiarities."
Mito raised an eyebrow questioningly, awaiting further explanation.
"I won't describe the effort it took to achieve artificial aging without tissue necrosis and without the influence of chakra residues, but the result was excellent — when my chakra acted on aging tissue, the cells started dividing again, getting rid of dead ones and replenishing the missing ones, which led to almost complete restoration to the state it was in at the time of extraction. It's quite obvious that the Uzumaki kekkei genkai affects the body, regenerating it to a certain extent even in the presence of signs of aging. Such an effect was observed only in this case, unlike with other living beings used as test subjects."
"And how does this help me? My kekkei genkai should work similarly, but because of the Nine-Tails' toxic chakra, it doesn't," Mito asked. "Most likely, only because of the properties of my chakra am I still alive, while an ordinary shinobi would have died long ago."
"All of that is true, but I have one theory," I shook my head, "you age faster than a typical Uzumaki not because the seeping biju chakra damages the body, but because the kekkei genkai doesn't heal it fast enough."
"What do you mean?" the kunoichi leaned forward eagerly, anticipating my answer.
"The chakra emanating from the biju seal, mixing with yours, most likely just neutralizes almost all of its positive properties, causing aging to occur just like in normal people. Thus, after extracting the Nine-Tails, there's an opportunity to reverse this process. The body can't do it on its own due to the almost guaranteed damage to the keirakukei, immense stress, and overall exhaustion after the ritual."
"That's where my seal comes in — with the additional infusion of chakra similar in properties to yours into the damaged channels, not only will the residual toxicity be removed and regeneration start, but there will also be a chance to restore all the positive properties of the kekkei genkai before the critical point is reached, after which the body simply starts to break down."