Prologue - A Shinobi's Origin...
It had been a peaceful last few decades. The endless cycle of violence momentarily on hold. Uzumaki Naruto was enjoying the life of a retired and dutiful grandfather. He had retired three decades ago and took to traveling the world and meeting new people, routinely returning to the village every six or so months to visit his family members or give advice to Sarada the current Hokage.
A few years had passed since Hinata passed away peacefully in her sleep, bless her soul. The children they had together had grown up and started families of their own. The village was thriving and everything seemed to be going well.
Then a few days later it happened. First was the message from Sasuke detailing the threat of a new enemy. Then there was the massacre on the moon with the remnants of the Ootsuki survivors forced onto the planet to escape the creature. And then it happened.
Sasuke was mortally wounded. The avenger's last act of redemption, giving his eyes to the retired Rokudaime Hokage to fight off this new threat.
Despite his old age Naruto still had power left in his body. The elderly sage and man would not stand by when there was some force out their threatening their home. So he would face it head-on.
Even if…even if on the off chance he failed, at the very least he could buy the five nations time to combat this new threat.
"Is this all the planet has to offer? Old men as their only defense?" The black draconic like mass taunted the blond.
As Naruto expected the creature was on the moon within where Kaguya was sealed. Segments of the mass body had been torn out.
"I won't bother offering you any chances to surrender. A merciless monster like you, there's only one way this exchange will go." His retirement and long life allowed him much time to sharpen and home his skills. Instantly Naruto activated the Paths' powers and began opening up with the Great Fireball Shower as the fireballs showered down at the mass. The creature reacted by lashing out with several dark tendrils but just as quickly Naruto countered with the Super Great Breakthrough attack.
The massive gust of wind did little to slow down the black mass.
"I see you're as strong as the other one. I better take this a bit more serious."
"Glad I'm not disappointing," Naruto replied, "Shinra Tensei!"
The jutsu blasted the being back sending him crashing towards the ground. Naruto leaped sideways over the bursts of purple crackling energy that erupted from the being.
"Bansho Ten'in!"
The creature was then jolted forward as Naruto flickered through hand seals and his hands lit ablaze with a Chidori before it plunged in the creature's midsection. It let out a warbled hiss as it lashed at the blond who jumped away. With these eyes. With these eyes, he could see everything, but trying to handle all the new visual data was causing him a headache. He needed to end this fight quickly.
He then boosted himself, delivering a kick to the creature's face sending it crashing back again. The creature was slow, but he was damn durable.
The creature quickly recovered as his mass shimmered and shifted. A massive wall of black liquidly darkness expelled from his body, covering an expansive range and heading towards Naruto.
Making use of the battleground's surface he erupted several earth walls to tank the attack long enough to get out of its range before the attack dissolved the walls.
Naruto's danger sense then went haywire, making him body flicker away from his current position, as jet-black spikes sprouted from where he was previously standing.
It was time to fall back on an old classic. Putting his fingers in the familiar cross sign an army of Naruto Shadow Clones appeared, creating multiple massive Rasengan as they used Hiraishin to dodge the creature's massive tendrils and weird energy bombs launched at him.
The attacks tore through the mass reducing most of the creature's body to shreds. Nearly all his clones were wiped out by the backlash. He wouldn't give this creature a moment to regenerate. He needed to hit it harder. Harder than any enemy he fought before.
Naruto began to gather both positive black chakra and negative white chakra around the Rasengan while adding the five main natures to it. The white sphere had a black core as it was flickering between the colors of nature.
It was just as Sasuke said. Each time the creature damaged its recovery time needed to heal was doubled. Just as it reformed and tried to defend itself Naruto shaped the attack into the form of a Rasenshurken and hurled it. The resounding roar of the attack echoed as the shockwave blasted Naruto backward and the light of the energy nearly blinded him.
He was nearly a second too late to avoid the crest that formed under him as he used substitution with one of the logs he had brought with him to the battlefield. The strange energy caused the log to darken charcoal black and thumped to the ground. That same weird char that had covered Sasuke's left arm and leg which post examination had revealed both limbs devoid of life completely.
"Kurama! Let's hit him with everything we have!" Naruto communed as they performed a perfect unison, the chakra blasting outwards and shaping into the form of the mighty kitsune. The Bijuudama that formed was nearly instantaneously as the creature let out some sort of chant in a language he didn't recognize forming five crests between him the Bijuudama.
The attack ripped through the four crests, slowly down after each quest before enveloping the last crest and detonating simply erasing the top portion of the surface caving into the small man-made structure.
"This…to think there was a mortal with this much power." The creature regenerated again, only being the twice of a normal human instead of towering over him like a behemoth. It had collapsed to one knee and seemed to be breathing deeply.
Naruto disengaged the Unison, not wanting to damage the shell that kept Kaguya sealed anymore then he did now. Creating a clone, he was already preparing not only another super-powered great spiraling sphere but also a sealing array to seal this monster like Kaguya if killing it was impossible.
"My mistress Nightmare Moon, forgive my failure to release you from your imprisonment early. Accept this failed servant, Shadowfright's offering as a potential concubine for your heirs and a slave to add his power to your arsenal." In this world lacking ambient magic resulting in less power than he was normally accustomed to. He would have to drag the creature to his world, weaken and capture him in hopes of this offering would please his mistress.
In the blink of an eye, a vast array of crests began filling the area. Despite Naruto's best efforts of landing his attack and nearly eradicating the creature to nonexistence he was enveloped by the strange energy and torn away from the area, away from his homeland, away from everyone he knew to parts unknown.