He was falling through an infinite abyss - but it was hardly an abyss. This place, their mind or collective consciousness - whatever you called it - was overflowing with thoughts, ideas, emotions, memories - and worse still, there was no real sense of direction, or reality; no firm ground that Sasuke could plant his mind onto, because this wasn't just an individuals mind. And the degree of information was much greater due to that fact - their interconnectivity. As he fell, or floated within it, whatever was going on since he didn't have any real sense of direction inside the genjutsu, and thus he could not even move himself very easily, he became aware of different individuals - sources of light and information that shined brilliantly for a moment before fleeing from him, quicker and much more adept to being in this state of existence than he ever could be.
There were rushes of information, loads of it, that drifted towards him like a cloud and went through him like the fiercest of storms he'd ever be able to imagine. It took everything in him not to lose himself and his own consciousness from the vast amount of data when it went through him, and being unable to direct himself away from it was not helping.
In addition to all this, he couldn't pinpoint Eien. He couldn't pinpoint anything, and he couldn't understand why this reality - this projection of Eien's mind, and all that she was connected to, wasn't even like that of a tailed beast. In those realities, those genjutsu, it was their innermost world - the places where Naruto or a jinchuriki would go to - that he'd see.
This was completely different... as if the basic effect of a genjutsu creating an alternate reality within someone else's mind failed to work on Eien. And that was precisely why he was having so much trouble, even with her not trying to fight him...
Within a few seconds, Sasuke became strained. It made Naruto a bit concerned, but nothing more could be done for now except to wait. Only if things got worse would he intervene.
Meanwhile, he tapped on Kurama's consciousness, "Hey, Kyuubi," he greeted the old friend.
"...What is it now?" The fox complained as it woke, "You see this?" He asked, inviting the bijuu to become aware of what was going on outside of his self-imposed existence. "Oh?" It was a sound of genuine interest, "Well, that's unexpected."
The Hokage turned and nodded, "And she let him do it," he was looking up at Kurama, questioningly. The fox knew that look, it meant the kid wanted something from him.
Setting itself down with chin in hand, Kurama responded, "What are you gonna ask me about?"
The blonde stumbled a little, "Well..." he began, "You really can't tell what's going on? There's no uh, new information or memories... you don't know anything about her?"
Kurama sighed. They'd gone over this a few times now.
"She's a part of the Shinju, same as us," he began, and it was true - the bijuu and Eien were connected to the same tree. And Kurama could sense her just as he could sense another tailed beast, but there was some markedly different about Eien that let him know she wasn't one of them. The nine-tails still couldn't quite pinpoint it, but there was one thing he did know about Eien that made her different.
"But with us, the Old Man changed the nine parts he separated from the Shinju so that we're not anything like it anymore..." Kurama's brow furrowed a little as he tried to reach deep into himself, to remember something about what it would be like to be a part of the Shinju. Nothing came up.
"Haven't you tried to talk to her at all?" He was asking about that plane of existence where all the bijuu can speak with one another. The nine-tails shook his head, "Nope, we can't - not like that, anyway." Naruto's face broke into a 'huh?'
'This kid... seriously...' Kurama still could get a little annoyed by him.
The fox sighed and flopped over, making itself more comfortable. "The bijuu share one place where we can all talk. Only we are connected to that, and well, you and the Old Man... point is-"Kurama still got a little irritated and excited at times. It was better than him getting angry though.
"-Eien's not a part of that. I've tried to call out to her, but she..." Naruto interrupted, "What?"
"I don't think she can hear us at all," Kurama finished.
There were explosions - or so it seemed - off in the distance. And they were getting closer. Sasuke tried to redirect his thoughts, but the explosions caught like wildfire and began to encircle him - as they grew bigger and brighter, and closer to him, he could see that they weren't really explosions - but more like flashes of light, similar to what you'd get out of a flashbang grenade. The force still rocked him once it came near him - and suddenly, his feet were planted on solid ground. "Finally," Eien's voice spoke, and he looked up to see her standing beside a woman with short, wavy brown hair - wearing a navy blue dress that he'd never seen the style of before. Her eyes were a tealish-blue, similar to the Kazekage's hue, except they had a clearly visible pupil.
It took him a moment before responding, and he'd realized that Eien had created this reality within her mind - she was going so far as to help him. "What is this?" He asked before looking around - they were in a massive outdoor library. Other people were around... and he wasn't entirely sure that his genjutsu hadn't been at least somewhat hijacked, if not completely. The fact that she had created this reality meant she was in the greatest amount of control - something the Uchiha was definitely not comfortable with.
"...Hell-o, Sa...suke-eee-ee..." The woman's voice came to his mind with a garbled, and delayed, grinding and shrieking sensation. It made him want her not to speak again. "What the hell is that!?" He demanded of Eien, forcing himself to focus on her alone - gaining access to her individual mind was what he wanted. Not to have everything else that came along with it interfering...
"This is Diane," Eien began, motioning to the woman beside her, "She's also part of the control cluster." Before Sasuke could respond, the woman's mouth opened but no sound came out of it - instead, he experienced a strange sensation as if time itself had been interrupted, then his consciousness was blasted off from the solid ground he'd just been standing on, and a shrieking filled his ears.
'Focus, focus... breathe...' the Uchiha calmed himself.
On one hand, being the first person since Obito, and before him Madara then Kaguya; to tap upon the Shinju's collective consciousness was a task not anyone can do. It is a risk, but one he'd decided was worth taking... Besides, Naruto and the other Kage, not to mention the entire Shinobi Union HQ was there, ready to fight Eien if need be or to tap on his shoulder should his body get too strained.
On the other hand, this was definitely revealing to him just why it was something that tended to kill people or drive them insane. And that was not going to happen to him.
Sasuke instead focused on creating a little reality of his own - it was a simple tactic when fighting for control during genjutsu: force your dominion, your will, into their mind by projecting something onto it with your own.
He manifested a world - something that began as a bubble before taking shape - similar to the neighborhood where Sakura now lived in Konoha. Something to ground him. The reality took shape, and Sasuke planted his feet on the ground - finally back in full control of his manifested body (the one inside the genjutsu) and his own mind.
"What the hell is going on here-" a woman stormed into the room with a storm in her voice, not that the extra stress was good for her at the time.
"Sakura-" the blonde began, only to be cut off by Kurotsuchi, "Sasuke is performing an investigation," and she in turn had Chojuro comment over her, "I don't recall that you were given clearance to-"
"Is clearance required to ensure my husband's health?"
There was nothing they could say to that. Sakura's medical skills were indeed of value to the HQ, and she'd only come with the Hokage because firstly, Sasuke was rumored to be travelling with the group overseeing Eien's arrival back to HQ, and secondly; she'd been working on and off with the Union on universal medical protocols for all shinobi in both combat and civil, home-based scenarios. The latter was something she'd had more success in outside of the Union, however.
Naruto had tried to talk her out of coming, only because at four-and-a-half months in, she shouldn't be moving around so much - of course the Hokage was threatened with some comment about if he was calling her too fat to move. Sakura was using her excuse to be angry indiscriminantly, whenever it helped to get her what she wanted. He'd just hoped that his long-time rival and friend wouldn't find out for better or worse...
Who knew if it mattered anymore, he was sick of walking on eggshells to a certain point. Somehow, somewhere, the Uzumaki just knew Hinata would not be like this. And he wondered if Sasuke would be sane if he were living in Konoha for the past few months.
There was a rippling around the very edge of Sasuke's fake-neighborhood as Eien entered it, placing her under his advantage. "You do figure things out rather quickly," it was the closest form of a compliment he'd ever heard come out of her. He kept his eyes on her, prying, trying to figure out if Eien was working with him or stringing him along. Just as he was about to say something, a larger bubble encapsulated his - someone else's consciousness?
There was laughter, like from an overly excited preteen girl, "What did I find, who are you?"
It was better than her asking 'what' are you... As the girl used to in her days of slaughtering.
This larger bubble was a lot more chaotic - and it messed with Sasuke's manifested reality, just enough to put him under strain. "Anemone, that's enough!" Eien called out with clear demand, and the chaos running through their smaller world stopped. "Aww, whatever..." The larger bubble detached, and as it did so, one last thought was transmitted audibly to them, "I'll go find Dominic, then... maybe Renton and Eureka too..."
The Uchiha turned back to Eien, "You're lucky to have survived her-" the hazel-eyed woman spoke, "Anemone's something of an antibody for us," that meant she was used to attack foreign invaders - including Sasuke or anyone else that would pry into the Shinju's collective mind.
"Follow me, I think I can find us a more secluded sector-" Sasuke interrupted, a billion thoughts were going through his mind, but he focused on the one most important thing: "Why is this genjutsu so different?" He would not move until she gave an answer. In the same question, he was wondering if this was what it had been like for Madara - or for Itachi, too.
Eien took a moment before responding, "Because I am human, and not a tree or a statue." His face would have broken into a 'huh' if Sasuke had ever allowed that sort of thing to happen, but instead, he just remained still and silent just as he had been before. "That's why it's different," she finished by turning to face him. "You can distrust me all you want Sasuke, but I know why you came here. So let's go and get this over with," as Eien finished that sentence, she turned and launched herself up and out of Sasuke's mini-world, encased in it's own bubble within the much greater consciousness of the Shinju.
He tried willing the entire reality to move, but that was impossible since he didn't have a clue about what was around that bubble. And so, he let it fall away after exiting the thing - keeping close enough to Eien's consciousness so as not to lose her. As they moved within the void, he could tell she was focusing, and the clouds of information and flashes of light lessened more and more until finally, they were pretty much gone.
"Alright," she said, "That should do," and with that, the woman began to project another reality-bubble around them.
He'd begun sweating.
And that had never happened before, but at least the man's eyes weren't bleeding. That was a good sign - and it meant a struggle of wills, but not necessarily a potentially lethal one. Sakura noticed Eien's eyes had a full circle in them - she'd been filled in of course, but to actually see it and in the present situation - with those eyes locked on one Rinnegan and one Mangekyo Sharingan - was a little unnerving. She had full faith in Sasuke, of course.
"By the way," Eien started before finishing her reality, "You're getting a little too hot, we really shouldn't let the genjutsu go on too much longer." Sasuke added his own will to whatever she was trying to do - he didn't want to get trapped in some kind of bad situation, "I'm fine," he insisted, to which Eien's will put a sudden vice-grip on his own, "No," it was strong enough that his own would not overcome it - Sasuke could tell - but she also was not intending any kind of harm or attack by it - "Your brain cells will start to die if your body temperature raises another two and a half degrees. And that's Fahrenheit," she added almost as an anecdote, then let go of that vice grip, finally fleshing out the reality that their combined wills were projecting.
Eien had a feeling this would be the case, but Sasuke was a little surprised by it - not that it showed, and that he let it give himself pause.
They were in a cave, one of many used by Akatsuki during the times when they'd controlled the Gedo Mazo. There was a life-like incarnation of Itachi, and Obito, in the cavern, which was well-lit enough since it wasn't like the laws of physics and actual relative lighting levels came into play here. They could make it as bright or dark as they wanted.
The statue was there too, with Itachi's hand on it, and Obito looking at him.
You could tell with a glance that they weren't the real deal - just a hologram, or something.
Sakura paced around the room, the genjutsu was taking too long and she hadn't seen Sasuke's body in this much strain during genjutsu - ever. And he had certainly never sweated, or had muscle spasms - though those were very few and slight, it was alarming nonetheless. Especially for how much could be going wrong.
The woman sighed and came over to him, putting her hand up to Sasuke's forehead - but without really touching it. "Sakura," someone began, "He's burning up," she commented, but had no real way to check any of his vitals without disrupting the jutsu. "We should do something," she said it with some anger but still the level of respect neccessary in her tone of voice. "Thirty seconds," Chojuro gave in, acting as diplomat for the couple - friends of his friend - and the more officially-inclined Tsuchikage.
There was a moment of silence that she interrupted, "I'm going to show you something now," Eien began, and before he could say anything, "And I'd like you to just not interrupt."
There was a tenor of pain in her voice, and Eien had walled her heart off to Sasuke.
He looked back at the fake Itachi, and nodded.
I closed my eyes and focused - allowing my will to influence this combined little world, something I never thought would have happened with this one's help. 'Just goes to show you,' I sent a private thought to Itachi's soul - wherever he was - imagining the guy smiling or laughing at my reluctance to do what I'd promised. That Sasuke would be the first to find out.
The statue's form became translucent, and he could clearly see the lumpy, white flesh-like substance within it, edging near the part where Itachi's hand had touched, and a sort of energy - there was a glowing connection between them.
It was not chakra, but it was having a very, very, small effect on Itachi's chakra system. Mainly in the heart and mind, but also all over - everywhere. And more than that, Sasuke could see changes in that energy - and in his brother's chakra system that made it look like they were communicating.
Just as he figured that bit out, the energies shifted. He saw Obito's chakra change, a flash of anger - this not being part of some genjutsu or whatever, just that Sasuke could literally see Obito's feelings and intentions. And he felt it, too.
Obito, back when he was 'Tobi', knew that Itachi had this different connection to the statue. He knew that if Itachi became connected to the white, fleshy substance that the connection would change - it would no longer be different from his and Madara's. And more than that, he was demanding that Itachi use this connection in a new way - to forcibly control some of that fleshy white stuff.
But there was a problem. Every time Itachi tried to do that, and even with Tobi's help; they had no way to forcibly control the white stuff because it was too mature - it already knew it's identity, and it was not going to change that identity in order to allow them such a full-level of control over itself, or themselves - whatever this was.
And so, they started investigating to see if there was any way to extract the white stuff - Madara had been able to because he had Rinnegan, and because he was the one who called the statue down out of the moon. That was one way.
What Itachi and Tobi found out, was the only other way was to create a new portion of the fleshy stuff - a new identity. A new lifeform.
Eien's abdomen glowed, the lower part where he might suspect the new form of life Sakura held would be. And at the same time, in the same hue of color, the statue glowed, too - Itachi's chakra and the strange energy from before - the trapars - were involved in creating that glow. Somehow, they'd managed absorb some of his biological data through the different connection. Or was it that just Eien...?
With that thought, and that realization, Sasuke turned to face her - but before he could get a good glimpse of Eien's face, the reality began to undo itself. The void began to undo itself, and he could tell he was getting out of this genjutsu.
His eyes wavered and the man blinked, then ducked and rescinded as if something had struck a blow to his forehead. "Sasuke-kun!?" A familiar voice greeted him, something he was glad for considering what he'd just seen.
He put a hand to his forehead, it was throbbing - his entire head felt like it had been in an oven for the past few minutes. "Are you alright?" Those mint-green eyes came into his vision, and Sasuke nodded, "...Yeah." Chojuro was about to speak up, when Eien began in a dead-to-earth tone, "We lost it," there was no emotion in her voice whatsoever, and Sasuke caught her eyes - they seemed dead in a way, too; but Eien was still very much there. Her eyes had broken into those half-circles again. "You understand me?" It was a rhetorical question, "That... it couldn't be allowed to be in the control of Akatsuki."
Everything clicked together then.
There was a time, after the first few jinchuriki had been killed and their tailed beasts absorbed, that rumors abounded that Akatsuki was possibly going to lose a very big investment. He remembered because it was about that time that the other nations were really getting concerned, and it was about that time that he began searching for Itachi, it was about that time that Jiraiya - his friend's greatest teacher - had begun seriously planning to find and kill the leader of Akatsuki.
That was because they - whatever it was within the Gedo Mazo - had lost a part of itself.