On another level

The sky was covered by thick clouds of ashes and smoke that rose from the always active volcanic range, and the sun that should have shone on the area was as such less than a suggestion when one tried to seek it. The world looked dim, and the only stretches of bright colour were given by the occasional streak of lava sluggishly running down the side of the volcano.

On a large plateau that had been raised with Doton from the side of the fiery mountain in question, a red-clad shinobi sat, his eyes studying the valleys below while his chakra churned violently, as it always did.

Roshi of Iwa was a veteran of a thousand battles: he had begun fighting in the last days of the Second Ninja War, only to live through the building tensions that led to the Third, and his village had nevertheless decided to put him aside, pushing him away from Iwagakure no Sato, only to be kept under guard by a selected group of shinobi.

He didn't doubt that they had precise orders were he to try and leave the country, or even meet with people they hadn't vetted. It had been more than a year since he last saw Han, his fellow Jinchuriki, and he knew that both had hoped for a change of pace after the death of Onoki, only to be, as he should have known, disappointed.

Despite the war, or maybe because of it, the two of them had been placed to ward sections of Iwa's territories instead of being deployed on the first lines: which was merely another way of keeping the 'monsters' out of sight, and out of mind, from the rank and file, while reassuring the populace that they were still working for the benefit of their Village. This wasn't untrue, as the volcanic range where Roshi had always resided since being dismissed at the end of the previous war was something he could hold with minimal aide from regular shinobi, while Han could streak through the plains at unrivaled speeds, able to mow any invading force before they could truly realize what was happening.

Still, an old, almost forgotten part of Roshi resented the number of reasons behind his and his fellow Jinchuriki' isolation. It was something that could hardly be addressed: The Power of Human Sacrifice was a less adequate title than most thought. After all, for all of the Yonbi's bloodlust, Roshi had never been able to project a killing intent that could rival Onoki's in his prime, and the dead Kage had been a mere human.

The endless series of self-deprecating, recursive and spiteful thoughts were broken when a lone figure suddenly appeared on Roshi's plateau: with a black garment covered with blood-red clouds, the newcomer stared impassively at the Jinchuriki, who didn't raise from his seated position, sure of his strength despite the vaguely unsettling feeling that accompanied the presence of the stranger.

"Oh?" the Jinchuriki tilted his head while scratching his red, unkempt beard: "You must be quite capable to sneak through the sensors posted around, and if you wanted to meet me, you should have simply walked in front of them, I would have accepted the invitation... who are you?"

The stranger tilted his head: "It hardly matters."

The long sleeves of his clothes hid his hands, but Roshi's chakra was already rising, building up not unlike the volcano they were on as he began to foretaste the clash to come: after all, for all of his isolation, the Jinchuriki couldn't deny the simple pleasure of testing oneself against an opponent, the uniquely pure thrill of a fight brought him back to easier moments, of when he was only a kid striving to do right for is home.

The banter was incredibly short-lived.

Roshi rocketed towards the newcomer with an explosion of chakra that cracked the ground, a trio of kunai flung ahead while fire nature chakra was shaped with the ease of a master with decades of experience: a concentrated lance of fire ran ahead of him, sweeping the area from left to right in order to force some movement from the stranger who had batted aside the thrown projectiles with contemptuous ease.

The stranger blurred out of existence, and Roshi kicked off the ground, changing his direction on a dime while leading with a backhand swing capable of breaking the neck of anyone but a fellow Jinchuriki.

His hand impacted only air, and Roshi received a singularly powerful kick to his midsection that flung him backwards, just in time to be stabbed in the neck by a kunai that had been struck mid-air by a shuriken that the man hadn't seen being thrown.

As the earth-clone crashed into lumps of dirt on the ground, a pair of hands rose from under Itachi's feet, only to grasp mere air once more. In a split second, the ambush tactic was turned into an area of effect attack: chakra pulsed with the discordant notes of fire and earth in it, and the plateau sunk inward, not unlike a sudden whirpool.

Roshi's chakra howled as he pulled on the Yonbi's might, and the world groaned as an answer: Itachi moved with controlled breathing, skipping on the momentarily still rocks even as he was dragged underground while he kept an eye on his target.

Without his Sharingan active, he was carefully taking stock of how his body answered his commands, of the incredible differences that properly oxygenated blood could cause after Daiki's intervention. The Uchiha's brand new lungs had no difficulty working in an environment thick with smoke and ashes, and where before he would have had to carefully circulate his chakra to remain conscious, everything now worked perfectly.

His chakra, denser since he had adapted to his new eyes, moved slowly and deliberately through his body, reinforcing passively every limb with less than a thought to be directed from Itachi. Even as the whirlpool of slag and rock dragged the entire plateau inside the hollowed-out volcano, the Uchiha was more focused on his body's answers than on his opponent, who was now openly pulling on the demon in his gut.

When the technique ended, Itachi performed a seal-less substitution with a lump of rock, his eyes briefly darting around while his chakra reinforced his body against the insane temperatures that were present so close to the pools of lava that littered the area: instead of a proper magmatic chamber, the area where Rochi had dragged the two of them had clearly been man-made inside of the volcano itself, and in the familiar surroundings, the Jinchuriki's bloodlust suddenly rose to inhuman levels.

"You're not the first trying to hunt me down, boy." the sneer on the Jinchuriki's face was twisted further into a grimace as two bubbling tails of red chakra blossomed from the base of his spine, and his voice turned into a lower growl: "You won't be the last."

Collected as always, Itachi distractedly marveled at the sheer novelty of having his body answer to his commands with no delay or no need for chakra to almost puppet it from the inside, only to bink, revealing a pair of blood-red Sharingan slowly spinning as he looked at his opponent.

Without missing a beat, Roshi's chakra burned angrily, snapping through the triple layer of genjutsu while he took a deep breath: with the same ease Kisame had manipulated water, the man dragged the lava around, and the name of the technique was lost in the crash of the rushing heat intermingled with the cracking of the stone. A bright orange armor of molten rock draped itself across his form while a tidal wave of the same material swept toward Itachi.

Inwardly grimacing at the not-effective tactics, the Uchiha blinked again. It went against everything he had worked to refine since he had understood what being a shinobi meant, since he had to carefully measure every drop of chakra available against the maximum effect he could leverage out of it.

And when his eyes opened anew, a different design was upon them: his Eternal Mangeyko Sharingan appeared not unlike a triskelion with sharp points in place of spirals, that curve inwards almost like hooks that stopped less than a millimeter from a single black ring that surrounded the pupil proper.

"Susano'o."

Moving about with the Hiding like a Mole technique wasn't particularly glamorous, but I made do.

Avoiding the sensor teams that littered the volcanic range that Roshi was guarding had been easy enough: simply tipping into Sage Mode was enough to let me feel them at impossible ranges, while keeping up with Itachi when he choose to actually sprint had proven way more difficult than it should have been. Then again, I should have expected it: regardless of the recent improvements, the Uchiha was the epitome of efficiency, while I had spent all my life finding loopholes to make myself into a juggernaut capable of withstanding the impossibly high stakes of the later stages of Shippuden, where assassin-like shinobi were comparatively useless.

I poked my head out of the inner side of the volcano just in time to witness Itachi forcing himself to spend chakra without a true need to do so: and I smiled. While his face was as impassible as ever, I didn't need to use water to boost my sensing in order to grasp just how much it went against his instincts to do so.

But when he called the Tempestuous God of Valour through his bullshit bloodline, I felt my breath catch in my throat: the wall of molten rock swept the area where Itachi was standing... only to part in front of a skeletal made of a fiery, red-chakra hand casually placed in front of my companion.

A comparatively small ribcage of the same chakra was wrapped around Itachi impassive form, while the gangly constructs of bones kept together by strangely mechanic-looking joints were being wrapped in the equivalent of tendons and muscles, only for a scaly armor to develop around them.

Roshi hesitated for a split second in his charge, and if this had been anything but a situation engineered for Itachi to actually test his abilities, I knew he would have been killed right then and there: I saw, from my vantage point, how Itachi's head twitched to one side, only for him to shake it self-deprecatingly.

The arms of the Susano'o rose while from the elbows a second set of forearms developed, chakra constructs appearing from an instant to the next in a display of power that moved something remarkably similar to jealousy within me, only for me to take a deep breath and drown the feeling: "Yeah, we can say I did good work."

Compared to the barely hanging there skeleton that Itachi had been, I was standing in front of an actual monster of the battlefield. But even as he swept aside a three-tailed Roshi, still clad in his magma armour, with his three stories-tall shiled, I spotted his unfamiliarity with dealing with so much power at his fingertips.

"Yasaka Magatama." the three magatamas bound together by a single, circular thread of bright orange chakra, were created on a single hand of Itachi's Susano'o, only to be flung above the ground in a sweeping arch that Roshi avoided by simply dropping into a pool of magma.

I whistled to myself at the display: besides the imperceptible hesitation in Itachi at throwing away what amounted to a chakra bomb, Roshi's display of control over lava spoke of a mastery attained through decades of tireless work.

The attack impacted the other side of the inner cave of the volcano, exploding in a rush of chakra that made me retreat immediately when I felt the magmatic chamber underneath shudder at the titanic-sized rocks that fell into it. Itachi should have thrown that through the ground, cutting a divot or opening a chasm.

But perhaps I was reading too much into it. Climbing out of the basalt that made the side of the suddenly rumbling volcano, my eyes darted towards the inbound shinobi that were tasked with offering aid to Roshi exactly for situations in which lone hunter-nins managed to sneak thus far, and sighed.

Well, there is always Han to get in some more practice. My chakra rose up and outside of me while I turned it into earth natured and began forming hand seals: at least I would get a warm-up by keeping outsiders out of Itachi's fight. Given just who we were preparing to fight, I needed him to know his new capabilities inside out.

Karin walked with her mind awhirl with the information that Tobirama was so eager to share, even if it had taken the combined effort of both Hashirama and Daiki to convince him. Her being an Uzumaki had likely been necessary for the Niidaime Hokage to decide to teach her as much Fuinjutsu as he could with the time available.

The two undead Kage ran at breakneck speeds for the kunoichi, but she knew that it was actually a speed they could keep up indefinitely even if they had actually been inhabiting bodies capable of getting tired, nevermind now that they were enjoying all the benefits of an Edo Tensei that Daiki had tweaked with Tobirama's assistance with the specific purpose of making them as powerful as possible.

Even as the trees rushed past them, the Uzumaki was re-interpreting everything that Daiki had introduced her to when it came to seals at the light of the clearly genius approach of the white-haired Kage, and she truly began to understand just the kind of abyss there was between a competent user of the Art and one that had a mind shaped to perfectly wield it.

Suddenly, the two Kage clad in ANBU gear broke to the left, and Karin inwardly cursed while trying to regulate her own breathing in order to follow them.

When she reached them, she couldn't hold herself back from gulping.

In a clearing, beside a forgettable brook, there were two shinobi clad in Akatsuki's garments: one had steel-grey hair slicked back, the other green pits in a red field as eyes. "Hidan and Kakuzu." she breathed out, her heart hammering in her chest despite knowing that these were exactly the people they had been looking for.

"Stay back girl, try to learn something." the curt order from the Nidaime Hokage was met with a mulish expression from Karin: it wasn't like she was eager to jump into a fight of this level.

"Kakuzu! I'm sacrificing...!"

While the Jashinist began spouting his nonsense, Hashirama had turned towards Tobirama, an unimpressed look hidden beneath his ANBU mask because of the way he had talked to Karin: "Brother..."

But he was already talking to empty air.

Tobirama darted out of the previously forgettable brook too fast to be followed, a hair-thin whip of water separating Hidan's head from his neck while cutting a divot into the ground only to crash harmlessly against the pitch-black skin of Kakuzu, who rose to his feet with threads already slipping out of his form, reaching for the Jashinist before retreating as they were cut down by an unimpressed Nidaime.

Then the attention of the oldest shinobi still alive turned towards Hashirama, who strode forward almost casually, his chakra slipping from his form, not unlike a cloud hiding the sun.

"This presence..." Kakuzu breathed out while Tobirama kept Hidan's head in a bubble of water that began to spin, stripping the flesh from the bones while it turned the crystalline liquid into a murky red one.

"It can't be." still clad in the earth-natured technique that made his skin impervious to damage, Taki's oldest missing-nin wavered in his determination, "I fought Senju Hashirama once, I won't ever forget it, but this..."

Hashirama extended a hand forward, finger poised as he took a final step: "I'm truly sorry, but I don't remember you."

From each of his fingers exploded forth a spike of wood, hyperdense chakra permeating each inch, and Kakuzu died with all of his hearts perfectly pierced by the only true user of the Mokuton, who then turned towards Tobirama, a sterner tone in his voice replacing the genuinely worried one he had used to address Taki's missing-nin.

"Try to be more polite, Tobirama!" he brought his hands on his hips, "We are to be an example for the future generations, Karin has a name, and you know it perfectly well!"

Off to the side, Karin's jaw threatened to fall to the ground.

AN

Yeah, we're getting there! This was more to casually showcase what Itachi is actually capable of when going in 'guns blazing', so very little tactics, while I also had Tobirama&Hashirama act using Karin as an observer.

Only a brief exchange for Itachi and Roshi: we're talking about a healed, EMS'd Itachi. He can only be defined as OP against anyone that isn't Madara, Nagato, or Obito pulling some tricks, and this is less meant to be a fight than it is to firmly set in everyone's mind that he's truly a main player.

I used Daiki merely as seasoning here, and in this fic there have been enough curb-stompings, I hardly need to add another.

And really, Tobirama and Hashirama have been fighting together back in the Warring Clans Era, they now have infinite chakra... and one of the two is Hashirama, which is the first Ninja Jesus fo the series, there just isn't a way for me to make interesting the fight: they win, period. So, I tweaked it in order to have finally a light shine upon Kakuzu's claim of 'I fought the first Hokage.

As always, opinions, hopes? Let me know!