Disclaimer: I don't own Naruto
This chapter was edited by PraetorXyn
Chapter 05: Hypotheses and Experiments
Despite my dislike for Naruto's living situation — with him having to live in a two-room apartment on the eastern edge of the civilian district — I had to admit it made finding him that much easier for me. All I had to do was look for a lone ANBU member perched atop one of the abandoned warehouses, and by extension, I would find him. Using Kamui to peek through the metaphoric keyhole of its dimension, it took me less than a minute to succeed.
The ANBU operative didn't even bother hiding, solely relying on a simple genjutsu altering the slope of the roof he was on so that his crouched self comfortably fit under the fake roof. Even were I inclined to forgive him for the use of a genjutsu that any academy student in their third year should be able to notice, I couldn't ignore the sheer hubris necessary to change the immediate vicinity of his charge's home — one that Naruto should know like the back of his hand — and think he would go unnoticed. This level of complacency should get him kicked out of ANBU immediately.
On second thought, getting your charge abducted right under your nose might make that happen regardless. The next few days certainly wouldn't be enjoyable for him, and if I were a more agreeable person, I might have cared. As things stood, he should call himself lucky that he was wearing a Konoha headband, and I couldn't afford to alienate the village… for now.
I materialized behind the rain barrel on Naruto's apartment roof, out of sight from the vantage point of the ANBU operative. Lifting one of my zōri while bending my knee, I reached for a small pebble embedded in the sole and removed it. It took me merely an instant to weave a complex sound-triggered genjutsu on the pebble, before I tossed it in a wide arc over the rain barrel at the place where the ANBU was hiding.
Straining my ears, I could hear the pebble land and then skitter to a halt. Only then I stepped out from behind my cover and briefly peeked in his direction to ensure that my genjutsu had taken hold. For the next few minutes, the genjutsu would block anything out of the ordinary from his perception.
The best part of the jutsu was that instead of just making him ignore something as much less complex genjutsu were capable of doing by altering the target's behavior, this one actually forced the target's mind to overwrite the reality of what he perceived. As a result, his memories of that event were consistent with how he experienced it, preventing mind readers and the affected from recalling what actually occurred at a later time.
If there was one thing I was certain of, it was that the moment Naruto's absence would be discovered this ANBU member would end up strapped to a table in T&I with half a dozen Yamanaka trawling through his memories, trying to find the one responsible.
Naturally, the objective was not to obfuscate who was responsible for his abduction. On the contrary, my plans required me to own up to the fact eventually. However, I needed to buy some time and direct the focus of attention onto Naruto's retrieval rather than the sudden disappearance of the Uchiha clan… even though they would be hard-pressed to dismiss a connection between those two events out of hand.
Nonetheless, my plan rested on the assumption that this would be enough to forestall the Uchiha Clan being declared traitors to the village with kill-on-sight orders issued for all of us until I was finished and could present the village with a fait accompli. With a one-handed cartwheel on the ledge of Naruto's roof, I softly landed on his terrace beneath, directly in front of his glass door. It took a moment to straighten out my kimono and cheeking for any tears the fabric might have suffered despite my best efforts to prevent it from being stained by keeping my legs together for most of the cartwheel. I was about to reach for the door handle when I caught a whiff of pepper. It immediately prompted me to freeze, and my mind went back to the conversation with my brother just a few hours ago in which he had described my Naruto as a trap genius.
It was hard to deny that he had made a good point when I nearly ran into one of them just now. Although, I had to admit I might be a bit rusty and hadn't been expecting any trouble at this stage of the mission. Even so, crafting a trap that nearly escaped my notice until it was too late was no easy feat: far from it, in fact. Considering that I only noticed it because he had used a component with a strong smell within a faulty packaging spoke volumes in itself.
For a moment, I pondered just using Kamui, making myself intangible, and stepping through the glass door, circumventing his traps, but where would be the fun in that? So, I took my time and inspected the door thoroughly.
Two things stood out: a barely visible trail of a powdery substance on the upper doorframe, and two small bulges close to each other — one above the door handle and the other at the same height on the frame of the inwards-opening door.
My initial assumption placed what I assumed to be a pepper powder concoction on top of the doorframe. It was supposed to rain down on anyone crossing the threshold. I also suspected the bulge on the door was the result of something like an anchor to tie a rope around, whereas the bulge in the frame had to be a hook to guide the same rope through. In most cases, this meant the rope would be wound around the trigger of a cocked crossbow or something similar, just waiting for the moment the rope was pulled taut.
It wasn't a bad trap. Simple, while still effective. Not in regards to killing an intruder — the pepper powder was an irritant at best if you allowed yourself to get covered in it: some watery eyes and a runny nose were not suited to stop someone for good. Besides, the kunai or bolt released from a contraption was hardly anything a run-of-the-mill chūnin shouldn't have any problems evading. Still, I doubted that was even the intended goal. I found it far more likely it had been designed as an alarm system.
A bolt or kunai being blocked — or hitting glass or wood — was hardly a silent affair, and pepper powder had the nasty habit of making people sneeze. The apparent way to avoid those traps by simply breaking the glass door would still end up serving the purpose of the trap by waking a sleeping Naruto, despite leaving the door untouched with neither the rope being pulled nor the pepper powder falling on the intruder.
The dispersal pattern from the thin trail of pepper powder I could make out on the door frame suggested that he had placed some kind of container on the door, which was most likely leaning against the frame. I was confident that if I opened the door slowly that I would be able to locate the exact position of the container and attach a chakra string to it to keep it and its contents in place. That left only the rope — and what was attached to it — to disable.
I figured that by opening the door a tiny crack, I should be able to squeeze a kunai in between and cut the rope before it went taut and could trigger the mechanism. Traps like this required a small margin of error so that they wouldn't be tripped accidentally via thermal expansion or the occasional vibration.
Picking the lock with a senbon barely took a second. I then slowly opened the door, just far enough that I could identify exactly where the pepper powder was located.
Just as predicted, there was a cylindrical container leaning against the doorframe. Mentally, I congratulated my Naruto for his choice of the container, because the round surface area would make any attempt to keep it in place with mundane means more difficult. Not so with a chakra string. Considering the fact that outside of Suna it was considered an obscure — and mostly useless — art, I could excuse this oversight.
With the threat of the container spilling its contents over me contained, I redirected my attention to the door handle and the cord I found there, just as I had expected. Lacking a kunai, I formed a short chakra scalpel at the end of my finger and was about to cut when I noticed a nearly transparent ninja wire running alongside the cord. I might have missed it without possessing a Sharingan and the superior eyesight that came with it, even when not active.
Curious, I closed the door a bit more as I watched the cord and wire intently. In response, the cord slackened; however, the wire stayed taunt. Ingenious: there was something hanging off the wire. This meant that were I to cut it together with the cord — thereby disarming the mechanism attached to the cord — it would spring the wire mechanism. If I had to guess from what I had seen so far, it might be something as simple as a bell suspended in the air from which — if the wire were to be cut — whatever hung would fall to the floor, most likely in a noisy fashion.
With a comprehensive understanding of what I was facing, I cut the cord and then proceeded, slowly opening the door until the pepper powder container above fit through the crack and could be guided safely into my right hand. By now, the door was far enough ajar that I could comfortably stick my left hand inside and close it around the wire. I cut it, too. Holding the wire in place, I was finally able to open the door, and I slipped inside.
As it turned out, my assumptions about Naruto's traps were relatively spot on, with some minor deviations. Instead of a crossbow, the cord led to a taut slingshot attached to a trigger mechanism, and the wire to a baby rattle.
With narrowed eyes, I lowered the baby rattle — painted with toad motifs — to the floor. If that was all Jiraiya could bring himself to do for his godson, he had utterly failed my already low expectations of him, and had just confirmed that it had been the right decision to lock him out of the Uzumaki compound.
I allowed my gaze to wander, in part wary of an additional layer of traps, and in part to get a comprehensive impression of his living conditions. To say I didn't like what I saw was an understatement, if there ever was one. I was downright furious that anyone would allow any child to live like that, and the fact that it was Naruto only made it worse.
The supposed living room was nothing more than a garbage dump. There was no way to sugarcoat it, because that is what it was. Dirty laundry carelessly discarded was strewn about the entire floor. The small table in the middle of the room was stacked with dirty dishes with food remnants still clinging to them in various stages of going stale. With the spread of spoiled food not limited to just the table, all manner of bugs were skittering around.
It was a result of Kushina's sense of chaos turned up to eleven combined with the distinct lack of common sense only a child could have. Someone had obviously failed to teach him that leaving perishable goods lying around wasn't exactly conducive to his health.
It took taking a tentative step into that mess for my nose to be assaulted by the abominable stink of all of this, which was magnitudes worse than any battlefield stained by blood and human excrement could ever hope to be.
Crushing a cockroach beneath my tōri, it became balefully obvious that everything my brother said — explicitly or merely implied — turned out to be true. I knew that things had been bad for him, but I had never imagined he would have been left to his own devices to such a degree. This went far beyond the attempted conditioning he mentioned. What had the Hokage been thinking?
I cut off my train of thought. There was no point in pondering that question, because it wouldn't matter after today: I wouldn't allow it to.
Entering the bedroom, the situation didn't noticeably improve. The only difference was that the floor was mostly littered with clothes piled up in three large mounds — one in each corner of the room not occupied by a bed — instead of old food.
Sprawled on it — with his blanket only covering one of his legs — was my Naruto. His left hand was laying on his stomach within his partly undone kimono. Seeing him like this — soundly asleep, his frizzly hair buried in his pillow, and a thin trail of saliva running down the corner of his mouth — the resemblance — short of the color of his hair — to Kushina was undeniable.
I would have liked nothing better than to watch him sleep like this for hours, but I regrettably didn't have the time. I was just about to cross the small distance separating me from Naruto when my instincts were suddenly screaming at me. Having escaped the clutches of death more than once by listening to them, I didn't hesitate for an instant and immediately became intangible using Kamui.
I had acted not a moment too late, because a lightning-clad hand emerged from between the valleys of my breast, followed by the rest of a body. The uninterrupted momentum carried my attacker straight toward the wall next to Naruto's sleeping form, not offering any meaningful resistance. It simply shattered on contact with the jutsu held in my attacker's hand, leaving a huge hole in his wake.
A heartbeat later, the sound of the impact — mixed with what sounded like hundreds of chirping birds — coming from behind reached me.
Midair — surrounded by dust and debris — my attacker twisted his body around so that his head — hidden behind an animal mask — ended up facing my way.
He hit the ground on all fours, digging small trenches with his limbs into it as he skidded to a halt.
By the time he looked back up from the glance he spared to make sure he hadn't screwed up his landing, he found Naruto's room empty of my presence, as I had reappeared right behind him. This granted him barely enough time for the muscles in his neck to stiffen in alarm before the senbon between my fingers were plunged into them.
To my astonishment, he somehow managed to start pushing his body off the ground and away from me, before the poison took effect mid-motion and his legs gave out under him. He collapsed immediately thereafter with his face hitting the dirt, dislodging his mask in the process. Lying unmoving and staring up at me with a Sharingan in his left eye was none other than Hatake Kakashi.
It was such a fortuitous encounter running into him here, saving me the trouble of having to hunt him down later on. Tilting my head, I kneeled next to him. "I am glad you decided to return my clan's property of your own volition."
His eyes widened in response to my words, but there was nothing he could do as my hand descended on his left eye and plucked it right out of its socket.
I took a moment to carefully examine the eye for any damage its prolonged stay in a non-Uchiha body might have caused. It was only when I was satisfied with its pristine condition that I called forth my Susanoo and added it to my collection.
Although I had expected Obito's left eye to be connected to his right eye's Kamui dimension in some fashion, the ability to open up a portal of varying size at range still came as a surprise.
"However, it by no means redeems your action concerning your treatment of Naruto, and there will be a price to pay for your neglect," I informed him while tagging him with a paralyzing seal.
With Kakashi taken care of, I surveyed the damage he had just done. With just a cursory glance, I realized that my plan to abscond with Naruto without anyone noticing his absence for some time had just gone up in smoke. What's more, I had my suspicion that the use of that signature jutsu of his might have left some characteristic traces. Since I would ultimately have to own up to Naruto's abduction, I absolutely couldn't afford being suspected of any involvement in Kakashi's sudden disappearance.
There was a marked difference between attacking your kin compared to attacking someone outside your clan donning a Konoha headband. As a result I was confrontedwith the question of what to do with him.
I couldn't default to my first instinct to simply kill him and leave his body here to rot. Altering his memories was also not an option, considering I had no intention whatsoever of returning Obito's eye to him. So, regardless of what memory I decided to implant in his mind to explain the loss of his eye, suspicion would still fall upon me — not to mention that it might tip people of that someone was capable of altering memories.
There was also a nagging question I desperately wanted an answer to: why didn't he take care of Naruto? To obtain an answer, I would prefer being able to take my sweet time to find it, by sifting through all of his memories —something that was best done in the relative peace of the Uzumaki compound, away from prying eyes.
Moreover, chances were I wouldn't like what I would find in his memories and — as a result — would have to dispose of Kakashi. The particulars only mattered insofar as to determine how much pain I would inflict upon him before granting him the mercy of death.
Then there was Naruto to consider. I would rather not have to alter his memories, and since Naruto had been watching the proceedings through the hole in the wall ever since my Susanoo disappeared, it was a warranted precaution. He shouldn't be confronted with death and the realities of life as shinobi for a few years yet. The less he knew, the better — especially if he shared Kushina's tendency to blab out secrets. Looking back, it had been a wonder her status as a jinchuriki had never leaked out.
Reaching into Kakashi's tool pouch, I retrieved an explosive note before I activated Kamui to make him disappear.
It seemed my introduction would have to wait. I then stood up and looked right into Naruto's eyes. Casting a simple genjutsu was all it took to put him to sleep. A moment later, I appeared next to him and caught his body as it was sliding to the floor. I carefully lifted Naruto up into my arms.
I created another Kage Bunshin and handed over the explosive note to her. She would wait here until my other clones succeeded in bringing in the stragglers of the Uchiha Police Force, and would then make sure to erase all traces of us ever being here.
Given Kakashi's actions, nothing short of blowing up the hovel they had made Naruto live in would suffice. That would alert the village higher-ups to the disappearance of the Uchiha Police Force when not one of them showed up to investigate despite the destruction of civilian property falling within their jurisdiction.
It would definitely shorten the time I had at my disposal, which was why I didn't linger.
With one last nod to my clone, Naruto and I were swallowed up by Kamui. We reappeared in the ritual room deep in the belly of the Uzumaki compound. I softly laid Naruto down near the first patch of the Uchiha prisoners littering the floor.
To my delight, two of my clones were already present and had begun with the preparations of the room and the prisoners. The small children and the few elderly at their feet alluded to which of my clones they were. With one of my clones still in the process of drawing the life transfer seal in the center of the room, I decided to take advantage of the waiting time.
First, I popped a soldier pill — undoubtedly not the last I would need to get through this night. The chakra expenditure of half a dozen Kage Bunshin for an extended period of time and the few small jutsu I had used up to this point were already taking their toll on my body. Age and relative inaction over the last few years were not doing me any favors either. Although, if those seals I took from Kushina's room worked as advertised, I just might be able to reach new — previously thought impossible — heights.
While a warm sensation was spreading throughout my body as the soldier pill did its job, I went ahead and began securing Kakashi's limbs. Unlike my kinsmen I couldn't kill him just yet, regardless of the outcome of probing his mind.
For one, I had to give his body the time to flush the poison out of his system. It was more than unlikely that anyone could tie the concoction back to me, but as one of the foremost poison experts in the village, I would end up a suspect regardless. This was especially true since my actions today would remind the village that I was still very much alive and more than a forgotten footnote in the annals of history.
Kakashi — despite all his faults — was a resourceful shinobi, and it would be foolish to trust a paralyzing seal to keep a student of Minato Namikaze immobilized.
There was also the problem of the decomposition of his body to consider. It would allow drawing an accurate conclusion of his time of death, and unfortunately, there were means to determine if a body had been put into stasis. For this very reason, I couldn't rely on sealing his body to obfuscate the time of his demise.
Still, I was getting ahead of myself. First, I needed to see Kakashi's memories in order to determine the extent of his guilt. With Kakashi's hands and feet bound, I turned him onto his back and forced his remaining eye open.
Kakashi's memories provided me with some very interesting events.
From everything I learned, two things stood out to me. Kakashi joining ROOT and the subsequent assassination attempt on the Third Hokage at Danzō's behest. In that instance, it wasn't the attempt that was unexpected, but that he had gotten away with it, as did the one who had given the order when both should have been executed. They weren't because Kakashi had changed his mind at the last minute and showed some remorse. This was a clear indication if there ever was one that the Third's sentimental side was a weakness, and this was only the most recent instance in which enemies had managed to exploit it.
Still, what had my blood boiling was learning that Danzō had held a Mokuton user within his ranks during the kyūbi attack. He had held the means to protect the village — to protect Kushina and Minato — and chose not to utilize them. It was because of him that Naruto had grown up an orphan. It was an unforgivable sin — one I would make sure he paid for in full.
Yet as much as I would like nothing more than to march right into his lair and find ways to redefine the phrase 'torture to death' with him as the guinea pig — a role he had more than just volunteered for with his actions — I couldn't. It was not right moment to do so, nor would it be for some time.
It all came back to us needing to rely on Konoha for protection. I couldn't afford to weaken Konoha any further than I already had. Otherwise, it might invite attacks from the other major villages and put Naruto at risk. No; I had to bide my time and gather more strength for Naruto's sake.
The first step towards that goal was to increase the quality of the members I had deemed had some future use for Naruto by promoting their eyes to the next level.
I had wondered for years about the particulars of the Mangekyō Sharingan. Not much was known about the requirements for gaining a specific ability. Even reading the stone slab after gaining an Eternal Mangekyō Sharingan hadn't provided me with a satisfying answer to the question. The absence of detailed records — most likely out of fear that they could be stolen and end up in the hands of our enemies — didn't help matters. My forefathers — if they had bothered at all — had been content with writing down the names of those who had managed to unlock their eyes.
Over the years, a small number of people had achieved it. Contrary to popular belief, Madara had not been the first to do so — far from it, in fact. It really should not have come as a surprise, as it was impossible to constantly wage wars against other clans without someone here and there going through the preconditions of witnessing despair to awaken them — which I now knewto be an inaccurate transcription.
Yet those who had — just like Madara — were infamous — reviled even by the Uchiha clan — and many had died at the hands of their kin — either slain for their crimes or their lost sanity — which had faded along with the light of their eyes or both. The difference between them and Madara — who had irrefutably carved himself a place in history by founding Konoha together with Hashirama and Mito — was they could easily be extinguished from recorded memory and subsequently forgotten. Unless, of course, you knew where to look — and happened to be the Clan Head's daughter.
What I intended to find out was if there was some kind of underlying rule set, such that it would allow me to influence or outright affect which ability one would gain when their eyes awoke.
What was it that determined it: personality, blood, or something else entirely? Kakashi's memories provided me with the last piece of the puzzle to form a coherent theory.
It was based upon two events, to be exact. Obito's presumed death — witnessed by Kakashi — made it clear that at the time his body had been crushed, my cousin hadn't had access to Kamui yet. It was absolutely inconceivable for any shinobi to hazard taking that kind of damage to their bodies if it could be avoided, and there was no doubt about it: his body was a mangled mess — Kakashi saw enough for me to be sure of it.
The second event was the death of Rin. With the sole exception of what happened to Obito, it was the only other event providing the required level of despair to advance a Sharingan to its next stage.
It was only a guess, but — given the situation they found themselves in when Rin threw herself in the path of Kakashi's jutsu — Obito also might have been present, because I really had a hard time coming up with an explanation as to how Kakashi — after he had plunged his hand through her heart — could survive that encounter surrounded by enemies as he had been. Someone must have taken care of them mere moments after he had fainted from the shock of his actions. Disregarding teleportation, this meant that someone had to have been close by — within sight of Kakashi and Rin — in order to be able to interfere in time.
If I factored in the state of the battlefield after he woke up — with the whole Kiri platoon butchered to the last shinobi, their blood and intestines littering the area — it all looked more like the work of a savage beast than that of a skilled shinobi. The restraint and precision that came with proficiency at killing were conspicuously absent. Instead, I noted an undercurrent of unrestrained rage.
The lack of variation or distinguishable patterns suggested a single perpetrator drunk on power great enough to casually overwhelm his opposition.
It was exactly what I would expect the aftermath of cousin Obito enacting bloody vengeance on those responsible for the death of his beloved Rin to look like.
The conclusion I drew from this was that the requirements for achieving a Mangekyō Sharingan with the ability of Kamui boiled down to the following. One set of Sharingan eyes had to be spatially separated, and both wearers needed to witness the death of a person they both cared about, at the same time. It was possible the person had to die at the hand of one of them.
This, in turn, meant that my running theory boiled down to the idea that the abilities granted by achieving a Mangekyō Sharingan were solely dependent on the specific triggering conditions.
The small sample size wasn't conclusive, and as much as I would have liked to view the memories of both my father and my brother, the risk of falling under their sway wasn't worth it.
This left putting that theory to practice, and as it happened, I had a whole clan of Sharingan-bearing shinobi lying at my feet.
There was only one thing left to do before I could begin in earnest: I needed one last tool. Luckily I knew exactly where to get it. A short walk over the paralyzed bodies brought me to my destination, where Fugaku's bound body was lying on the ground. I momentarily paused, savoring the knowledge that the last thing he would ever see was me looking down on him. Bending down next to him, I plucked his eyes right out of his fear-stricken skull, thus sentencing him to spend his last moments in absolute darkness. I couldn't think of a more fitting punishment for someone who worshipped our eyes.
Calling forth my Susanoo, one of its many limbs reached for Fugaku's eyes resting in the palm of my hand and inserted them into one of the countless empty eye slots it possessed across its body. The effects — just as they had been in the previous instances — were immediate, and I instinctively learned the basics of his Mangekyō Sharingan abilities Tsukuyomi and Amenominakanushi.
At the moment, I didn't care much for the latter, and just acknowledged it being added to my repertoire. Tsukuyomi, on the other hand, was exactly the tool I needed. A jutsu able to trap the target after eye contact into an illusion of the user's design, powerful enough to make them experience days worth of torture within a single moment, and able to inflict a tremendous amount of psychological damage to the recipient, putting them into a comatose state. It was next to impossible to escape the effects of Tsukuyomi because of the nearly instantaneous speed it worked at, rendering the usual methods to combat genjutsu useless.
All these qualities made it one of the most powerful genjutsu in existence.
However, I wasn't interested in the damage the jutsu could cause in a fight. I was far more interested in the limits of the illusions themselves — especially in regards to how convincing they could be made — because if I could manage to make them indistinguishable from reality, they then could be used to make the chosen ones of my kin go through their customized experiences of despair. Hopefully, this would allow me to trigger their Mangekyō Sharingan.
This would also allow me to test my theory about the same trigger conditions being responsible for the same powers.
Conditions that — in the case of recreating Kamui — weren't easily met. There was no shortage of Sharingan — allowing for plenty of transplants — but I only had one pair of people I could be reasonably sure had the same deep-rooted feelings for the same person. Unfortunately, those feelings were not of the romantic nature as I suspected was the case when it came to Obito and Kakashi's feelings for Rin, even though the latter was in denial about them.
Akane and Aoi were identical twins. Their father had gotten himself killed a few years back shortly after the twins' birth, leaving their mother with the responsibility of raising them both on her own. He was one of the few fatalities we suffered outside war, which took a special kind of incompetence. Luckily, the children showed no signs of inheriting any of their father's less desirable traits.
Their mother had been a relatively competent tokubetsu jōnin until her retirement following her husband's death. She was the only person the 4-year-old girls had any sort of close relationship with, so by creating an illusionary repeat of the event that led to Obito and Kakashi obtaining Kamui, they just might end up with the same eyes.
Should the illusion fail to be convincing, in the worst case, I would have to make them reenact it in reality. It would be a waste of a perfectly healthy body, but at the end of the day, it would be worth it.
I found the two girls one of my clones had stolen from their beds and deposited on the ground. Akane — in her genjutsu-induced sleep — was still clutching her stuffed cat to her chest.
They both looked the same since I last saw them, wearing their Uchiha black hair in mirrored asymmetrical lobs, with a bang running alongside their cheeks to help anyone who wasn't their mother tell them apart.
I went down onto my knees and moved Akane's bang out of the way to allow me better, unimpeded access to her right eye. Using my left hand, I parted her eyelids, severed the optic nerve, and removed her eye. I then proceeded to Aoi and repeated the process of removing her right eye and began the arduous and time-consuming process of implanting the eye in my hand. It required the careful reconnection of every single strand of the eye's optic nerves to their corresponding counterparts. This was no easy task, because a single mistake could have devastating effects on the eye's abilities. It was the first time my self-taught medical knowledge was actually put to use. I had originally started to dabble into it a few weeks ahead of Izumi's due date. Given the scar this left me with, I had intensified my efforts ever since.
When I finally finished after half an hour, I repeated the process and subsequently implanted Aoi's right eye into Akane.
It would usually take at least a week until a medic would allow someone the use of a transplanted eye. The nerve strings — even with the help of iryō ninjutsu — were raw and brittle until they had the time to fully heal, and any premature use could hamper the healing process and increase the chances of an infection. This was an undeniable fact that wasn't helped by the antirejection medicamentation the recipients of transplants had to use for the rest of their lives.
The medication was wholly unnecessary in their case — with them being identical twins — and another reason why I chose them for the procedure despite their admittedly young ages. Depending on the outcome of this experiment and the Mangekyō Sharingan's abilities each eye would manifest, they might have to keep an eye on their sister. Even if my theory turned out to be correct, it was formulated upon the observations made regarding one pair of Sharingan split between two people and not two pairs as was the case with them.
Regardless of the outcome of my experiment, I would rather avoid burdening them with medication that would weaken their immune systems, which might have an undeniable impact on their general health and endurance, amongst other things, preventing them from fully realizing their combat capabilities down the line.
Even so, it would still leave them with two injured eyes, which shouldn't be strained in the foreseeable future to prevent damaging them. Raiding Kushina's room provided the perfect solution to this problem.
A solution which — as the telltale sound of a Kage Bunshin dispelling and the memories that came along with, informed me — was ready to be used since the sealing array was finished being drawn.
Each of my hands reached around the twins' small hips and lifted them from the ground when I stood up on my way to the center of the room. I placed Akane within the bounds of the recipient circle of the sealing array while the currently last remaining clone of me present in the room unceremoniously threw down Fugaku into the donor one.
I took a step back — moving well outside the bounds of the seal — holding onto Aoi while my clone went for the control array of the seal. It was located between the two circular transfer endpoints and activated the seal by channeling some chakra through her feet into it.
The array lit up, and what looked like a yellow ethereal substance was making its way through the sealing array on the ground from Fugaku's side to the twin. It showed a remarkable resemblance to blood traversing a vein.
The difference was that instead of sustaining a body with oxygen, this one transported the life force from one side to the other. It took just a few moments of the seal running at a low setting for the effects to become notable. I watched with bated breath as — in slow motion — Fugaku's hale and hearty body turned feeble. His hair turned white, and the few small wrinkles on his face multiplied and became deep gouges littering his face as the life was literally sucked out of him. He more and more resembled a raisin than a grape.
On the other side, the effects weren't as pronounced. From where I was standing, all I could tell was that Akane had gained an increasingly healthy complexion. I would have to wait for this to be over before I could do a thorough examination of the twin to say more, but it seemed the seal was working as advertised.
I turned my attention back to Fugaku, not wanting to miss a single second of his demise. He ultimately didn't last long, and if not for my Sharingan burning every gruesome detail to my memory, I would have been vexed at how fast it was, not giving me the time to truly savor the process.
My clone went to the lifeless husk that had once been the man I had been forced to marry and sealed it away. The clone replaced it with a female roughly the same age as Fugaku and removed her eyes with surgical precision. Meanwhile, I switched out Akane with her sister, and we started the process again. Mere moments later, we had a second body that was also sealed away and had to be disposed of later, just like Fugaku and the many others who would follow him into death.
I would probably resort to the use of fire — not because it was tradition for the clan to burn our dead, I couldn't care less about that — but the tinge of poetic justice it invoked was a different matter. Burning the old and decrepit and building something new — nurtured by the fertile ground provided by the dispensed ash of their bones — seemed like a fitting end to my father's legacy in more than one sense.
Crouching down next to the twins, I took stock of their condition. The diagnostic scan of their bodies not only told me that their implanted eyes were fully incorporated and ready to be used, but that there were other changes. At first glance, they might seem inconsequential: improved blood circulation throughout their bodies, an increase in red blood cells and muscle fiber density, and bone hardness. For now, those changes were small, their bodies facilitating them by burning through their stored resources. I could only assume that those changes wouldn't be fully finished for another few weeks, depending on their food intake during that timeframe.
It was truly astonishing. Seeing these effects, it became clear that the prolonged life expectancy was only a side effect of an overall improvement of the recipient's bodily health. This would undoubtedly be reflected in their overall combat power, since those changes would ultimately help boost their endurance, speed, and chakra.
It was more than I could have hoped for and made me wish — for the first time in my life — that my clan was bigger than it currently was, with more bodies to spare.
My musings were interrupted when another of my clones appeared via Kamui inside the room and deposited another batch of people and a scroll containing the assets of the raided homes on the ground before dispelling immediately afterward. This was the last of my clones to successfully return from collecting clan members from their homes. Only those in the Uchiha police station and the one I left behind to blow up Naruto's living accomodations had yet to accomplish their tasks.
Stimulating the eyelids of the twins with a bit of chakra ensured that they would stay open for the next few minutes, even in their unconscious state. With the final step of my preparations done, all that was left was figuring out if Tsukuyomi was up to the task.
The vast experience in using genjutsu and manipulating memories I had accumulated helped a great deal in crafting the illusion. The first part of the illusion was a short fight against a faster opponent relying on barrages of countless senbon. Projectiles that were notoriously hard to make out — thereby straining their eyes while also putting them under emotional pressure with their sibling present and in need of protection — did the trick of awakening the Sharingan in both of them.
Designing a scenario to awaken the Sharingan was simple enough if you had no regard for the child's wellbeing. It had been a common practice back in clan-era days for parents to force the issue. The clan had numerous instructional guides regarding the topic stashed away. Each method seemingly tried to outdo the other in cruelty that could be inflicted upon the children with varying success rates.
It was the second part of the illusion I was anxious about. I kept the details mostly the same as what Kakashi could remember from the encounter. I only replaced Rin with the twin's mother, and then put them both into the illusion. I was careful to ensure that they then went through the events concurrently, just from different points of view. Akane was the one to accidentally kill her mother with a kunai while her sister Aoi observed it from nearby.
The whole proceeding didn't even take a second. The very instant I cast Tsukuyomi, it was already over, both of the twins' eyes advancing to Mangekyō Sharingan state. The appearance of all four of them was identical to the pinwheel pattern of Obito's eyes.
The activation and subsequent advancement took a lot out of both of them, leaving their bodies at the very brink of exhaustion and severely depleting their chakra. It was difficult to imagine how they would have fared before they had received Fugaku's life force, strengthening their own. It didn't bode well for the other younger girls, but that was a consideration for later.
At present I was more interested in learning more about their eyes. Diving into their memories and listening to the exact moment their eyes advanced — and whispered to their subconscious what they are capable of — confirmed my theory. In addition, it became apparent with their eyes — not only possessing the same ability as Obito's, but also possessing the same distinguished pinwheel pattern — that those two things went hand in hand, and were solely dependant on the triggering conditions. This allowed someone familiar with all possible permutations to be fully aware of what they were facing with just a glance at the eyes. Unless, of course, that glance turned out to be a fatal mistake. Even Eternal Mangekyō Sharingan wouldn't be exempt from this phenomenon since their pattern was a simple fusion of the two respective Mangekyō Sharingan patterns making it up.
There was another interesting tidbit of information I gleaned from this: both the twins manifested only one ability each. Akane got the ranged Kamui attack in her original left and the implanted right eye. Her sister got the intangibility touch version of Kamui in her original left and the implanted right eye, and neither could manifest a Susanoo, which I assumed could only be done with eyes belonging together.
In order to prove or disprove that theory — which should help deepen my understanding of our bloodline — the twins needed their original eyes back. The process of carefully removing and retransplanting them barely took me a minute. As a result, each of the twins — once again — ended up with one eye that was in no condition to be used.
Luckily, I knew how to solve that problem, and so did my clone, who correctly deduced what I was planning and anticipating my needs had prepared another two of my male kin. The only use any of them had in the Uchiha clan I envisioned — subordinate to my Naruto — laid in their eyes and the life force they could offer to strengthen those worthy. I would strip them of both until nothing remained.
After my clone placed the first body stripped of his eyes into the sealing array, I activated it. The effects it had on the donor were exactly the same as Fugaku and the woman suffered before: his shriveling to a life-less husk within mere moments. The effects on the twins compared to the first time were negligible. Their bodies visibly recovered from what I had put them through, but this time there was no immediate change in their complexion. It wasn't unexpected: there had to be a limit to the amount this seal could help a recipient already in peak physical condition.
When the array shut down with the death of the donor, I went to both of them and conducted another examination of their bodies. As it turned out, receiving a second dose of life force expanded upon the changes from the first, increasing most bodily functions even further. This confirmed that the sealing effect was indeed cumulative.
Unfortunately, I had no way to tell what impact the ritual had on the twins' life expectancy. It might have added ten, twenty, thirty, or even more years to their lives, or in the best case might have added the donor's entire lifespan as advertised. It was unlikely I would ever be given the opportunity to find out for sure, because not would I have to outlive them, but also given the danger of our profession, neither of us dying a violent death at some point was an unrealistic expectation. The only thing I could say with any certainty was that it most definitely wouldn't shorten it, and it gave them an edge, which was a more than sufficient reward for a resource that I would otherwise be squandered, since I would have killed them all anyway.
With that question answered, I turned my attention back to the twins and once more dived into their memories, looking for another whisper. It took me a while to find it, as it was quieter and buried deeper than when their eyes had first advanced — even more so than whenever a Mangekyō Sharingan gets added to my collection — but it was unmistakenly there.
Once again, I was proven right, and each of the twins was now equipped with a pair of Mangekyō Sharingan able to perform both Kamui jutsu and the ability to conjure Susanoo — the latter being a necessary requirement in order to gain an Eternal Mangekyō Sharingan. No matter how powerful Kamui was, it wasn't worth being stuck with eyes that would eventually lose their light.
The conundrum was how to proceed from here. I was reluctant to advance their Mangekyō Sharingan to Eternal Mangekyō Sharingan using someone else's Mangekyō Sharingan, despite the abundance of people with Sharingan all around me whose eyes could be put toward that purpose. Something was stopping me.
It wasn't the time it would take me to achieve it that was the problem, since I wasn't under any time constraints. At best, it was a soft one rather than a hard one, since it would politically hurt me to delay owning up to my deeds, and it would make negotiations about the clan's future more difficult. Other than that — and the added risk of someone escaping, either through an ability advancing their eyes might grant them or during one of the breaks I inadvertently would have to take to do so for the over 500 members of the clan — there was no logical reason not to do it.
All I had was a gut feeling. No, it was more than that. Ever since I had implanted Naruto's eyes into my Susanoo, there had been a connection between us. It was faint, and without all the other eyes as a comparison, it was doubtful I would have been able to tell it was even there, to begin with.
Still, for there to be some kind of link made sense. As Obito's case had made clear, a pair of Sharingan remained connected to each other even if spatially separate. So it stood to reason that since his regeneration made sure he wasn't limited to just one pair of eyes throughout his life that all his eyes were connected.
His eyes were special, just like he was.
I had known that from the moment I had first laid my eyes upon them. The raw power they had emanated had been beyond even my late father's Eternal Mangekyō Sharingan; it was hard to imagine what they would be like should they ever evolve. So I was more than just confident they would more than suffice to preserve the twins' light — even though it would come at the price of their eyes not gaining any additional abilities, instead of the possible five jutsu remaining at just the current three.
Then again, it was three extremely powerful jutsu. Most — if not all — of them would never have unlocked them, if not for me, and perhaps something would come of this. While I had to admit the chances were slim that the twins would somehow benefit from this in the future beyond not going blind, the same couldn't be said about Naruto. After all, there were some undeniable similarities to the triggering condition of Kamui.
In the grand scheme of things, if limiting all their eyes to just three Mangekyō Sharingan abilities instead of the possible five held the potential — regardless of how slim — that Naruto would profit from this in some way, I would always consider it a price more than worth paying, and would gladly do so a thousand times over.
My mind made up, I ventured over to a sleeping Naruto.
After steeling myself, I began the grueling task with the help of my clone of harvesting his eyes. By the time I had collected both of his eyes and had handed them to my clone, one of his eyes had already fully regenerated, allowing me to extract the second pair without any downtime. I didn't linger next to him for long and only allowed myself to briefly caress his cheek, fearing that if I did, I wouldn't have the heart to do this… over and over again… until all of the chosen were seeded with his eyes.
Both my clone and I returned to back the twins with our respective bounties. Carefully prying open one of the twins' eyes each with my index and middle finger, I used Amenominakanushion them both. Their eyes immediately became milky, and their pupil was overlaid with a shadowy resemblance of the Mangekyō Sharingan pinwheel the jutsu originated from, displaying its use for everyone to see.
Unlike Kotoamasukami the jutsu didn't subtly manipulate the target's mind, and instead suppressed most of the conscious mind, thereby turning them into nothing more than puppets whose strings were held by the user of the jutsu. They were forced to obey every command given to them.
It really shined when it came to combat applications; being able to hijack an opponent's body with a glance was nothing to scoff at. Even though the jutsu could be dispelled, it was easier said than done. After all, there was a huge difference between disrupting the chakra of a willing ally and that of an enemy, especially if that enemy had access to nearly their full range of abilities and was constantly hurling jutsu at you. The added disregard the hijacked had for their own bodies only added to the danger. That it was most likely this jutsu which was ultimately responsible for the kyūbi attack was only of academic interest at this point, because by the time the day was over, nobody with access to the jutsu — or the potential to awaken it — would be in any state to threaten Naruto ever again.
At least it appeared that way, because with this, I had added the eyes of two of the three known users of the jutsu to my collection, and Madara had been dead for decades.
Still, there was some lingering doubt. I had only been able to retrieve one usable eye from cousin Obito, with the other one closed from what I assumed was the use of Izanagi — the eye which had to be the one to cast Amenominakanushi on the Kyūbi, because his other eye was only able to use Kamui.
Not that it stopped me from implanting it into my Susanoo in the hopes of getting something out of it, which to this day hadn't happened, and after nearly eight years of nothing, I doubted that would ever change.
Nevertheless, with Obito's other eye having been gifted to Kakashi, it begged the question as to where he got his second eye from, and what happened to its counterpart. Quite a shame, since it prevented me from finding out who it originally belonged to.
Minato must have really done a number on him if he was forced to rely on that jutsu to sacrifice what at the very least must have been a Mangekyō Sharingan, and still lost. Still, Fugaku — the only other wielder I knew of — was no longer an issue.
With control over their bodies, I forced them to summon the first stage of their Susanoo and directed the chakra construct to implant a pair of Naruto's eyes into the empty eye sockets each. The whole process barely took a full minute, but when I relinquished my control over their bodies, they conked out, and their small bodies trembled uncontrollably.
I didn't even have to examine them to identify the symptoms of acute chakra exhaustion. My clone didn't waste time, and went to prepare another few bodies to relieve their suffering. I, however, just stood there replaying the exact moment they reached the Eternal Mangekyō Sharingan in my mind. The glimpse I caught in their eyes was not something that should have happened.
From my research over the years poring over old dusty scrolls, I knew that when two Mangekyō Sharingan were combined to create an Eternal Mangekyō Sharingan, their respective patterns merged into a new one signifying their evolution. They didn't talk about the three pinwheels, the tomoe of the Sharingan turned into multiplying into six and then three of them spinning until they overlayed the three original arms and became one.
I would have expected to see a six-armed pinwheel Sharingan if I had given the eyes of one of the twins to the other in order to create one pair of Eternal Mangekyō Sharingan, but that was not what happened, and even if it had, it wouldn't have explained the subsequent merger.
I waited with bated breath for another transfer of life force into Aoi to be over and Akane's turn before I began my investigation. Diving into their minds, I nearly missed it. Only the thought of what the Eternal Mangekyō would have turned out to be had the twins' eyes been combined lingering in my mind allowed me to notice the subtle differences in the whispers of their eyes.
They didn't tell of any additional jutsu they were now capable of, but they did mirror each others' capabilities. This meant that both of their eyes were able to utilize each of the two Kamui jutsu — Naruto's eyes creating the exact same result I would have gotten had I combined both the twins' eyes into one.
Suddenly, using his eyes didn't seem like such a bad idea. Sure, it was still a reduction in options open to the wielder with only having three instead of five jutsu. Still, considering that losing an eye — which was a real possibility in a battle — would reduce five to two and three to two made the trade-off seem was a wantonly underestimated concept.
I reached for the scrolls I had taken from Kushina's study and unsealed their contents, and two cylindrical objects appeared. I picked up the first one and imprinted it with my blood. Object in hand, I went over to Naruto. A small incision on his thumb provided me with a few drops of blood, which I used to imprint him as the second user of the tool supposed to apply the seal to our eyes. The rest of the blood I applied to the stamp carrying the seal to ensure that only his seed would ever take hold in the womb of any Uchiha woman.
For the finishing touches, I applied both seals to safeguard our bloodline to the twins. After one final examination of their bodies — in which I found no cause for concern regarding the seals — I used the first tool while looking up and applied it to both my eyes. Then I unwound my kimono to get access to my stomach and applied the second seal on top of my navel. Unlike the seal to my eye, this time I felt something: a warmth spreading throughout my lower torso that grew increasingly unpleasant. It was as if my insides had been lit on fire, curling up in the fetal position because of the pain. I couldn't stop cursing myself for my utter stupidity, overlooking the fact that I had given birth, and — despite my virginity technically intact — I was not untainted.
Of course, a seal from a patriarchal society that treated women as nothing more than cattle would take issue with that. Just before the pain grew unbearable and I thought I might die, the pain stopped, and the heat in my guts disappeared as suddenly as it had begun.
Righting myself, I grudgingly acknowledged that I had been lucky. This mistake could have cost me — and Naruto — everything. As the sole person standing between him and the village, I had to do better. I owed that to him and his parents.
This realization made me reconsider messing with the last seal from Kushina's room before I had the chance to completely look it over.
With that taken care of, the only thing left was ensuring their unquestionable loyalty to Naruto. Given that every clan indoctrinated their children to various degrees, it wouldn't take much to achieve that: a few minor tweaks to their memories here and there would suffice. Some added narrative painting Fugaku and the elders in a bad light trying to usurp me would answer the question of why they had needed to die, and we had aligned ourselves with Naruto. I also erased the unsavory memories of what I had put them through.
Under normal circumstances, this would be as far as I would go, but this was not about my sensibilities. This was about Naruto's safety, and for that, there was nothing I wouldn't do, no line I wouldn't cross.
This was why I tapped into Kotoamatsukami. Unlike my late father, I wasn't content with relying on some badly worded suggestion to force their compliance: loopholes and unforeseen circumstances conflicting with the orders given were just too much of a risk. Instead, I chose to go with what my father should have used on me — even though I was glad that he hadn't — and made the twins love Naruto with everything they had.
This was not entirely without danger either. Obsession had the potential to become a problem on its own. For that reason, I went to great lengths and curbed their capacity for feelings like jealousy as much as reasonable, and added loyalty towards the clan — and especially towards Naruto — in equal measure.
This should prevent any unforeseen accidents, and since I had every intention to monitor those changes and adjust what I did to each individual girl as needed, I didn't expect any real problems to occur.
Wiping away the sweat on my brow, I let my eyes wander around the room. 50 more to go, meaning another 50 more Tsukyuomi to trigger their eyes, another 50 more Amenominakanushi to call forth their eyes, another 50 more uses of Kotoamatsukami, Amenotokotachi, and Kamimusubi to alter their minds. I had a long and exhausting night ahead of me.
I was reluctant to do the same to the youngest children; the strain of a Susanno forcefully conjured would likely be enough to potentially harm the permanently, if not outright kill them. Even in the best-case scenario, I expected a severe case of chakra exhaustion, and as a result of that for them to fall into comas; their chakra networks and tenketsu were just not mature enough to sustain such a highly demanding jutsu. Their deaths — should they occur — would be a heavy hit given what I had planned. My plans made every single girl a valuable and rare resource, and squandering them lightly was the last thing on my mind.
Nonetheless, it couldn't be helped. I had to do this now, fully aware of the risks.
With our clan's strength diminished, we found ourselves in a very perilous position. Fugaku and the elders were known traitors, to the Hokage at minimum. This could mean that rather than allowing me — an associate of theirs —to stay in charge, they might decide to simply dispose of me and start over themselves and rebuild the Uchiha clan how they saw fit.
This was a possibility I couldn't simply discount, but it was a course of action I was certain I could dissuade them from even considering by placing as many hurdles as possible in their way, to the point that dealing with me would be far less of a headache for them. Among other things, it meant not a single Uchiha would have unprotected eyes, ensuring that no one besides those born with them could ever make use of them. This alone would go a long way toward making us a less tempting target for their machinations.
This was especially true since a woman or girl used as a breeding stock had no need for eyes, which made protecting our eyes a valid concern. Danzō, in particular, struck me as someone who wouldn't be above such methods if they furthered his goals.
Then there was the fact that leaving the girls with just a Mangekyō Sharingan heavily limited the use of their eyes throughout their lifetimes, and sentencing them to a slow descent into blindness was something that left a bad taste in my mouth.
The existence of a key to the seals protecting our eyes meant that it could easily be fixed at a later date, allowing me to unlock Naruto's — or anyone else's — eyes should the need arise for some intact eyes to advance a Mangekyō Sharingan to an Eternal Mangekyō Sharingan. So the logical thing would have been to postpone the procedure until they were older and their bodies were able to take the strain.
The problem was that I had noticed when I had gained Obito's eye — and later my fathers's — that the hold Kotoamatsukami had over me slipped ever so slightly in response to the power of their eyes being added to my own. Given the power held within Naruto's eyes, there was a chance that by advancing their Mangekyō Sharingan to an Eternal Mangekyō Sharingan that the sudden boost to their power might weaken or remove the adjustments I had made to their minds and memories. It was a risk I simply couldn't take.
My hold on them needed to be absolute. Otherwise, they could become a potential threat to my Naruto.
Hopefully, by strengthening the younger girls beforehand by transferring the life force of one or two people, the worst might be avoided. The Uchiha clan — as of yesterday — had 598 members; minus my father and brother we were left with 596. Yet only 56 — including myself — were of any future use to my Naruto. That left me with 540 spare bodies. If I fed the life force of 7 others to each of my 56, that would leave me with 148.
It would probably be prudent to give the more talented members like Izumi and Shigure a few more to strengthen them further, perhaps even to Satsuki. She was in Naruto's class, and if I couldn't pry him out of the academy, she would be all the protection he had for most of the day. Given her mediocre talent, she would need all the help she could get to not slow him down.
So, if I gave those three an additional three, that left another 39 for me, and the rest I would use on Naruto. It should more than makeup for what I would have put him through by the end of the night by extracting 56 pairs of eyes from him.
Just imagining what heights this might allow him to reach had me lick my lips with excitement.
Authors Note:
The idea of different triggering conditions resulting in different MS abilities was something I first came across in the story "Time Braid" by ShaperV: a Sakura-centric and very interesting and IMO enjoyable take on the groundhog day trope.
I found the whole thing a great idea, especially since it neatly fit with pretty much everything we learned throughout canon about the MS.
As you might have noticed reading this chapter, I'm not a fan of the plug-and-play Sharingan mechanic that was depicted in Naruto canon, where you could just grab an eye, put it in your eye socket, and it was ready to go. One has to wonder why Sasuke had to run around for a couple of chapters with his eyes bandaged after getting his brother's eye. Then again, Kakashi also didn't need any downtime after he got Obito's after an operation that couldn't have taken hardly any time.
Sure, there is their supernatural healing Iryō Ninjutsu and such, but that was outright ridiculous. It is the same with having a foreign organ in your body not having other consequences like the need for immune suppressant medication and everything that entails, in addition to the other downside of the Sharingan sucking up more chakra when in use.
Still, the whole thing just rubbed me the wrong way. I mean, if there are seemingly hardly any downsides with the Uchiha not bothering to safeguard their eyes, why weren't there more Aoi just with Sharingan running around (long before the Uchiha massacre)? Surely Uchihas weren't unkillable. It just didn't make any sense.
And with this, I at least tried to offer what I think is a plausible explanation that no matter how good a Sharingan is, implanting one could actually make you weaker than you were without one. This would also explain why Orochimaru wanted an Uchiha host, because an additional chakra cost of a Sharingan implant never seemed to be that much of a hindrance in a world with cursed and chakra-storing seals. Worst case, Orochimaru would just have to grab himself some host body that had great chakra reserves, like an Uzumaki.
Amenominakanushi: Since this jutsu has the potential to start a controversy, let me explain my reasoning for why I saw the need to introduce it into the setting. As we learn throughout canon, every pair of MS grants the wielder three abilities: Susanoo, and then an additional one for each eye. Yet somehow, additionally, they are able to control bijū.
This never sat right with me. I mean, why? How does it work? What makes the bijū so unique that this jutsu only seemingly works on them? (Yagura was apparently controlled via his bijū. This is another strange occurrence, since Bee states that a perfect Jinchūriki — which Yagura is said to be — should be immune to the effects of genjutsu. Unless, of course, he was only ever a perfect jinchūriki because of the genjutsu he was under)
There wasn't a single answer, despite "because that's how it works," which essentially goes against everything else we are told of the MS, and therefore was not something I could just accept. It always felt like that hinted-at fourth ability that someone who managed to get an EMS was supposed to get, which was sort of forgotten later on… probably after Kishimoto finally settled on the IMO lackluster Sharingan mechanics we saw throughout canon.
The means to control bijū obviously couldn't have been something like Kotoamatsukami, which was stated to be unbreakable (I mean, if it worked on Edo Tensei Itachi, and was considered as a solution to the Uchiha coup, it sort of had to be IMO. Then again, Mifune was freed from its effect — if that was even the real Kotoamasukami that was used on him) because the kyūbi could be freed from its effect. Furthermore, it created a very distinct Sharingan pattern in the eyes of those under its sway. So instead of just attributing that to a nameless MS ability that only worked on 9 beings in existence, I decided to streamline it and made it into a full MS ability in and of itself.
As the chapter explained, it is a jutsu that instead of manipulating or controlling the mind of someone, simply takes over their bodies and — to a certain extent — their subconscious, thereby allowing the puppeteer to make use of the full range of the puppet's abilities.
Among other things, this means that one of Madara's EMS abilities was Amenominakanushi, and that Obito must have not only used this ability on the kyūbi, but also must have had two eyes when he confronted Minato and Kushina. (Bear in mind that I consider the Rinnegan to not be the final stage in the Sharingan's development, but its very own dojutsu)
I probably should also explain Mikoto's reaction to learning of Tenzō here, which some of you might call unreasonable. Mostly because Tenzō — during the Kyūbi-attack — was around 8 (at least according to one timeline — canon contradicts itself in that regard) So how could he have made a difference?
The thing is, Mikoto is aware of that fact, but truth to be told, she doesn't really care: she has desperately needed someone to blame for what happened to Minato and Kushina, and by extension to Naruto for some time. The more she learned about his life, the more the guilt was pressing down on her shoulders, because she could never shake the what if of the situation. What if I had been a bit faster, what if I had been able to break the genjutsu, what if I had been more docile, would I still have been under that particular genjutsu, etc So, of course, she clung to the first hint that it might not have been her fault at all, even though deep down, she might know she was just lying to herself. That is how the human mind works.