Author's Note: This is set in an AU of what I could see happening in the future of the series. For this short story (it'll be three chapters), we're beginning before Kawaki and Boruto fight in a destroyed Konoha, (SPOILERS if you don't read the Manga) but after Jigen has sealed Naruto away. I'm taking liberty with the plotline, character development, and some abilities. Also what I see as a hint towards resolving certain inconsistencies (coughcough CURRENT ANIME coughcough). This is more of a worst-case scenario/cosmic horror theme, because IMO, there really hasn't been too much evidence as to WHY the Otsutsuki threat should have scared Kaguya in the past apart from her being a klepto with chakra. So be warned with that. I appreciate feedback, and thanks for reading!
...
Naruto's right arm hung limp, his Six Paths Sage mode and the natural energies collected no longer binding back the flesh and torn muscle visible in the back of his armpit. While the blood that continued coming forth had slowed to a trickle, it was steady enough that the Hokage couldn't ignore it and the multitude of wounds that had been inflicted upon his person. Even those that had first been wrecked upon his body, long ago in being sealed here, had yet to completely heal.
To his side, a scowl presented on his raven-haired friend's face, an expression mixed with annoyance and – as only Naruto could see – distraught.
There had been a moment of relief upon first seeing the Uchiha, though it was short-lived as their enemy – their captor – soon after followed. It was clear Sasuke didn't have the chakra reserve for another space-time jutsu, and in retrospect, unlikely that he'd intended to come here himself. The space-time manipulation had clearly not been his own in arriving, after all.
Jigen had shrunk the rods imprisoning Naruto, releasing him. "The Uzumaki tenacity lives up to its name," he'd commented, as Sasuke briefly moved to a more defensive position and took a moment to check in on the blonde's condition.
"You didn't expect something like that to kill me," he spoke while wiping his chin, giving the Kara leader a stern look. This time, there was something more… off about him. The Uzumaki hadn't the moment to really contemplate it, as Sasuke spoke, "Whatever you're planning-" "has already come to fruition," the Otsutsuki vessel interrupted, his voice lacking intonation, "You are powerless to stop it."
A motion, and suddenly their missing chakras were restored, "Though I welcome you to try." This had been the beginning of their battle, one that had drawn out longer than any before, one that even with their full abilities returned, did not allow them any chance at escape. Somehow, the Uchiha's space-time ninjutsu seemed nullified in this place. 'Did he allow my escape before?' This was the first of several alarming inconsistencies to cross his mind during the long fight.
It was now, in another moment of pause – Jigen clearly toying with them, drawing out their efforts at self-preservation, making clear, visceral, and absolute his supremacy over them – that Sasuke glanced at his friend, fully knowing what their final options were.
Don't.
That's what the Uchiha's face was telling his friend, the man's body battered and pushing beyond its limits for too long. Naruto could only chuckle internally and wince a bit as he made to stand, a mixture of the pain from his side and the difficult, if not ultimately rewarding, memories they'd created.
This world was his home.
Like hell the Uzumaki wouldn't fight to end things here. And of course Sasuke knew it.
No matter the cost… everyone in the village was his family.
And his son… his wife and daughter. His friends.
Not to mention what this bastard would do to Kawaki, now that he'd been taken by Kara again, as Sasuke had informed.
There was of course, the alarming fact of what Jigen had already done to another Juubi – or at least something very similar to it. But this... this wasn't the way things were going to happen. Kara would not have their way.
The Uchiha held back a grimace, recognizing the fact of what was about to happen. The dichromatic readied his blade as the old teammates stood, both of them cognizant of the fact that this abomination before them was simply allowing that to happen. It wanted them to stand, and then to crush them.
The familiar feeling crept over him, and a glance to his side confirmed it: Naruto grinned, the trademark expression that had both gotten him into so much trouble, and gotten him and his loved ones out of impossible situations in the past.
The smile that said both, "I've got us", and "I understand you".
They knew they were in trouble before, fighting Kaguya, then those that had come after her.
They had both felt fear for each other's lives in facing Jigen before.
But never had Sasuke felt such a true dread and concern for what was to come next.
Not since he was much younger…
Then the words came,
"You're wrong," a simple statement, as always.
The thing before them did not react, and Naruto lifted his gaze to challenge it: "Shinobi are stronger than you could ever understand, it won't matter if you can stop us," his tone and stature strengthened as a shimmering orange began to take form around him.
Even with what this Otsutsuki vessel had done, still they pushed beyond it – their chakra gates damaged, their tenketsu mostly clogged. It didn't matter, they still had their pride, their abilities… they still had their lives and their hope. Even if it was so dire of a chance… the pair would stand and fight.
"You can't put out the fire in our hearts!" With that, a resounding – almost deafening – roar of chakra enveloped him, the combined efforts of Kurama and all that had been gifted to him through Rikudou Sennin. It settled over him in blazing golden-orange, the tattered Hokage's cloak now redeemed through this sudden outpouring of pure will in the blonde.
The words he chose echoed his predecessors, referring to Konoha's great 'Will of Fire' and to the fact that, for everyone – throughout all the shinobi nations – Naruto was regarded as a hero, no, as their very sun.
The Otsutsuki within their foe caught wind of that, their natural insight bringing to the thing's mind exactly what the Uzumaki was referring to, exactly what the challenge and promise was that Naruto was making here and now.
Somehow, those obsidian orbs twinkled – the unfathomable depths set within them skirting apart for a brief moment, allowing some twisted perversion of the life that had once been, now warped and shifted to act merely as a tool for an abomination, to respond: "Your sun orbits a black hole that will eventually consume your entire galaxy; it has already devoured millions of stars." There was a plain, matter-of-fact coldness to his words, succinct and without any hint of intonation or expression whatsoever.
For a moment, Naruto's expression shifted – he blinked as the odd sensation of something being deeply off, wrong, even out of place and not belonging in Jigen crept up once again.
"This is the natural order of things, this is the nature of all Creation," the man's right hand twitched, setting the shinobi present on defense even as it raised without any indication of gathering chakra for an attack. "Your universe will succumb as all others before it, giving rise to something new," the Otsutsuki vessel smiled, "I am merely accelerating that process."
His delight in sharing that revelation was enough to turn their stomachs and set the defenders on edge. There was something deeply wrong in him, as if Jigen's mere existence was something the Universe itself were crying out against. His eyes and expression were those of a predator taking in the sight of wounded prey, before savoring a finishing blow.
"You can't possibly think you could control all of that," the Uchiha spoke, a slight strain and concern in his words at grasping the fullness of what this thing had implied. Surely… a goal of working on a galactic scale? Even Universal? That couldn't be possible for any living thing to ever achieve.
Within a fraction of a moment, the pair of voided orbs set their focus upon him: "There was a time your people considered one who possessed chakra as a goddess. There was a time my own people considered the God Tree as something it is not," again, the emotionless, purely logical syllables fell into place. "I am not surprised that you failed in obtaining it," a personal attack this time, intertwined with the general message. The Uchiha shrank back slightly, unwilling to push that edge – unwilling to look too closely upon it, the similarities between what he had once called for – in revolution – and this demon's will.
The Uzumaki noticed this, and with a frustrated grimace returned his focus to their greatest foe, "You're the same as all the others," the blonde rebuked, "only-" Before the Hokage could continue, their enemy rushed forward, continuing the onslaught and seemingly intent on prolonging this test of endurance.