28/13/2018 Story edited with a background to how we think he's the ninja we know.
A hail of ice needle was upon the two young ninjas. One in a bright orange outfit with blond hair & reddish eyed slit pupils and the other blue outfit with dark hair & Sharingan activated.
The Uchiha pushed Uzumaki away to take the brunt of the attack as Sasuke felt that he was able to see the ice needles about to make the hit. In a moment of unpredictability, Naruto used a technique to switch with Sasuke. With the sudden change, Sasuke was not prepared and got knocked out by landing roughly and hit his head.
Naruto had become a life-sized pincushion. The hunter-nin was slightly shocked nonetheless taunted Naruto.
"Ninjas are simply tools there is no need to sacrifice yourself for a lost cause."
Hearing such words made a crack into Naruto's mind as red chakra started to enveloped his body with the wisp of it whisking away. His outfit's color slowly fades away as well as his features are changing with sharper nails and fangs. A low growl emanating from his mouth with a hiss produced by rapid healing melting the ice needles.
Sharp gaze toward the hunter-nin who let out a small gasp and settled into a throwing form in the preparation of subduing Naruto. The mist was decreasing from the heat of Naruto's cloak letting Sakura capable of seeing inside the dome of mirrors.
Meanwhile, Demon of The Mist attempts to kill Tazuna and would have succeeded if not for the timely interference by his opponent who received the blow instead. By sheer luck, Sakura blindly released a Kunai and scratched Zabuza arm.
A fight renews as both get into a stalemate with neither having the upper hand.
Later, the mist slowly lowered to a seeable level as Sakura saw Sasuke on the ground with superficial wounds all over. A rip spot on his shirt slightly bleeding had reminded her of when she saw him from a Genjutsu she then screamed.
"Sasuke!" Screeched Sakura as she dropped to her knees.
In turn, a momentary pause in the battle between Demon of The Mist and Copy Ninja.
"Heh, my apprentice should win over by now."
"My team are en-"
An explosion of chakra soon followed as a fox-shaped head appeared over the dome of ice mirrors. The shattering of ice sounded throughout the bridge multiple times from Naruto punching mirrors before hunter-nin escapes for another mirror.
"Shit," Kakashi prepares to move, but was prevented by Zabuza, "Your team seems to have some trouble dealing with my apprentice Kakashi (insert laugh)." Using this opportunity, he creates a clone to distract Zabuza.
Hiding behind a small Genjutsu Kakashi summons his dogs to hold Zabuza in place. Taken by surprise, he allowed Kakashi enough time to activate Raikiri. Making the motion of going forward with his technique Haku appeared roughened up and took the hit.
Before Haku was able to do so, Naruto managed to distract Haku long enough for Demonic Mirroring Ice Crystals to appear few centimeters closer between both Kakashi and Zabuza. Haku shows up as Raikiri lands a hit barely missing Haku's heart.
Grabbing hold of Kakashi's arm Haku passed out to let Zabuza a chance to kill him. Using this to attack Kakashi who hugged Haku and quickly backed off. Laying Haku down, he retaliated by disabling the sword arm. Luckily, his other arm was disabled as well by summon dogs for Kubikiribōchō unusable any time soon.
Starting his finishing blow the sound of tapping prevented him. The surrounding mist disappeared letting him turn his gaze, scanning the direction of tapping. Able to hear steps getting closer towards them.
At this moment the sound of clapping was heard. He found Gato and his goons coming towards them.
Gato in front of mercenaries said, "Well, he's certainly made a fine mess out of you!" Tsk, tsk, "What a pity..." walked closer towards were Haku currently lays.
Telling his change of plans and wanting to eliminate them he noticed Haku with a gaping wound believing to be dead. Decided to make a kick he was stopped as a shuriken was close to harming him. Looking up Naruto was seen in a throwing position breathing deeply.
A little angry (slightly scared), by his stare with red eyes as his form, shimmers due to lingering mist he commanded his army to eliminate them. His army rushed towards them with weapons at hand numbering on hundreds filling part of the bridge.
Kakashi with blood loss was unable to move as quickly as he hopped and Zabuza did not have enough energy (endurance) to stop them. Sakura was guarding both Sasuke & Tazuna. Naruto... he just plainly grabbed a handful of shuriken and threw them with enough force that few passed through them.
In a run, he used Shadow Clones to make a perimeter and shuriken he thrown before unhenged and attacked once more from the inside. With one appearing behind Ganzo as it took the opportunity to kill him once and for all.
Two-thirds killed, and the rest are damaged. Thanks to previous battle and summoning shadow clones Naruto chakra levels are almost upon depletion that gravity seals in his outfit and weighted inner armor deactivated. A lucky guy punched with brass knuckles using great force leaving Naruto to skid over where Kakashi was fighting.
Going to his knees coughs up bile and wobbles to collapse making Kakashi eyes widened, "Naruto!" then runs to prevent him from falling.
Making eye contact, he replies in a half smile, "Ninjas endure... ri-" and passes out. His image momentarily flickers, as his eyes turn back to blue, for a second showing his true appearance with a body similar to Nagato (from Shippuden).
Kakashi would forever see this as he was using his Sharingan to combat the army in his weakened stated. He also noticed a seal at the base of his neck while holding Naruto from long ago in relation with an organization that should have disbanded. He checks his pulse to make sure he is okay as the red chakra formed a thin layer then disappears.
At the same time, an arrow landed on an enemy making them all turn to the gathered villagers with weapons on hand. They yelled from a distance, and the remainder of Gato's army decided to scram from Wave. Seeing them leave the villages celebrated their victory and were still wary of Zabuza still alive nor attacking.
A small girl named Ageha appeared to move in front of the crowd next to Inari who loudly called out "Big brother!" And Ageha looked around to see Naruto with his eyes closed on the floor. Both Ageha and Inari ran towards where Naruto is as they are worried about him. Ageha got something from her pocket, and it was a pair of goggles and placed it on his chest.
Surprised by what she did, especially that she had it thought Kakashi. Inari was flabbergasted and said "huh?"
"He helped me from a bad man being a meanie and gave me snacks;" she showed a small orb, "that he said it was to give me energy, but dropped this as he ran off to here earlier," Ahega who got shy from their looks shyly said with her clothes a little roughed up.
Kakashi was shocked at the pills she brought out ignoring "Sasuke! You are alive! (insert fangirl scream)!," with Sakura hugging him to death. Sasuke woke up from all of the commotions. With Zabuza approaching Haku whose currently laying down passed out due to electrical shock and stabbed his sword to sit while leaning his back on it.
'Oh god, those are pills exclusive to the Akimichi and outsiders are not capable of acquiring them... how did he?" With an eye smile, he told them that the celebration is for later and its time to rest.
A month before Kyuubi's attack
It was raining that night making the technique sound like a flash of thunder over the area.
The brightness from flashing, repeatedly along with thuds and silent screams, was heard near a cliff on VotE. Bodies laid on the floor wearing black Anbu uniform and blank mask belonging to Root thanks to the legendary Flying Thunder God by Fourth Hokage. Finished dealing with them he heads for their leader.
Coming closer to Danzo's position where he backs away for the edge of the cliff. Danzo cursed as he thought back to how it happened when Minato showed up after getting wind of their still ongoing operations which was considered disbanded a year ago as his first order as Hokage. Raiding his hideouts and taking everything of use as he gets his men into rehabilitation with the Yamanaka Clan.
For him to escape his punishment this time, he left with few men with some men at the hideout. Minato chased after where they ended up in VotE.
Minato unleashed his special kunai and Rasengan, timing it exactly where lightning struck between them making Danzo react with enough strength to put his arms in front of him. The Rasengan manages on disabling Danzo's right arm and his right eye before the cliff they are standing dislodged itself.
Not able to do anything with pain filling his senses Danzo kept falling. Minato himself was going to check on him before his Anbu arrived and reported Mission success and that his wife is in her mood swing and knocked out someone. Chuckling at his wife antics while watching for any signs on Danzo he left when there was none.
Rewinding a minute, Danzo was about to hit the ground until a sensation of being lifted and feeling his senses when traveling quickly noticed that he was over someone's shoulder. Looking at the face of his savior chuckling was heard, and a child-like voice ask "Who is he, Kenny?"
"That's my, former boss that I've told you about." Danzo eyes widened as he realized of his only remaining living member of the team he once led during the war with the samurai regiment.
Night of Kyuubi's attack
The Kyuubi was released to the world and under command, of an orange masked man in attack Konoha without its citizens knowing what was going on. Minato manages to get the perpetrator off-guard and dissolved his connection with the tailed beast via summoning jutsu. Kyuubi in the middle of making Tailed Beast Ball and releasing it where Minato manages to divert it to another uninhabited location.
With no other choice of defeating such beast Minato's wife thought of taking with her Kyuubi to death as a reprive of delaying the inevitable. However, Minato with clear conscious plans for something outrageous.
"I'm going to seal the rest of your chakra inside Naruto. It'll be part of an Eight-Signed Seal. And then I'll take Nine-Tails with me using the sealing jutsu that I can do, not being a Jinjcuriki the Shikifuijin Reaper Death Seal!
"...! But that jutsu results in the Caster's Dea-"
"If done correctly I would be able to seal both our chakras to the seal as a countermeasure if needed meaning that one day we're able to see our son all grown up. Furthermore, I'm only going to seal away its mind so that it won't actively harm Naruto."
"The future would fall into harsh times... let's believe in our son," Minato starts to make the hand signs Snake, Boar, Sheep, Rabbit, Dog, Rat, Rooster, Horse, Snake, "Reaper Death Seal!"
"Why sacrifice for the sake of balance! For the Country or Village! Even for my sake!" huffing after saying her piece.
"You know why, of all people, you should know there's no difference forsaking children and one's home as we are called Shinobi for a reason as we endure what we face." Both not noticing the slight opening of their child's eye as he heard that one piece of reasoning and then drifting off to stay awake and falling asleep.
Minato was able to seal away the Kyuubi at the cost of both their lives as they save their son from the attack of Kyuubi who noticed their attempt. At the point of dying and saying farewells to their son that she mentions, "Just be careful, don't fall for the first girl that comes your way..."
Watching all of this was a man thought once dead named Danzo as he walks up to Naruto and creates a seal using the blood of both parents and any lingering Kyuubi's chakra. A Genjutsu type seal where it uses both Naruto's chakra to power the seal and Kyuubi's as backup.
After completing his objective, he stands to full height and says "take care of the rest Kenpachi... no, Teuchi." Picks up his orange mask and disappears.
A week after Gato's death
Team 7 are about to leave the bridge and back home, but were stopped as Zabuza and Haku appeared in front of them. The team noticed that Haku's hair was now shoulder length. Wishing each other farewell and Haku thanked Naruto at the last second with a kiss at his whiskered cheek and disappeared.