A Possible OP Story I've Been Adding To Now And Again...

Secret of the Otsutsuki

Disclaimer: I don't own Naruto or One Piece.

"…I hate growing old," he rasped, mostly to himself, the warm air feeling rather cold and painful in his harsh breathing. And he wouldn't begin the mental tirade about the aches and pains everywhere else in his body. It wasn't just the age either. He'd done a lot in his years and it showed, wearing him down to this day.

If he timed this right…

Breaking the tree line, he came upon one of the islands less accessible coves, hopping down the steep descent to the beach. It was only ever used by locals as it opened out onto shallow-watered reefs for miles and miles. Many a pirate ship had tried coming that way in ambush only to lose their ships and their lives to the ocean's treachery.

It was also why he expected the massive ships to skirt area, giving it a wider berth. With all that was going on, the chaos and destruction, he just hoped that he could accomplish what he knew needed doing.

Huffing and puffing, practically flying over the sand, moving pretty well for a man of his advanced years if he'd say so himself, he came to a sudden halt adjacent one of the small paddle-boats pulled up on the beach.

Now it was that he paid mind to the bundle that he'd slung over his shoulder, for the first time since he'd seen the fiery carnage wash across his village. It was a young child, no older than seven or eight by his appearance, with highly distinctive sunny-blonde hair, and a trio of whisker-like facial markings across his cheeks. Laying him down in the bottom of the boat with all the care of a man bidding farewell to someone near and dear, he passed a quick, unquestionably final glance across him. Gods, but he looked more and more like his father every day. And so much of his mother in every act…

Cruel or not, what he intended was the best chance the boy had of surviving what had landed on their shores, and Hiruzen knew it. Hordes of their own were already dead, more dying still. There was no going back from this. It was triage at this point; save those you can. No matter how few.

As one last grandfatherly act, smiling a little in remembrance, he doffed his hat, the hat of the village elder, and placed it atop the unconscious boy's head. "Goodbye, dear boy." Stepping back around to the nose of the boat, he brought his left leg up and placed his foot gently against the keel. "Survive, my boy." Shoving the small rowboat with all the might that his old bones possessed, throwing all the Haki he had remaining in him behind it, he sent the craft skimming across the sea's surface.

He hadn't even time to grab any food for the child, save the flask of water the old man kept with him on his average day. His only hope would be for the boat to drift close enough to an island.

A lot of ifs in that plan.

More than an old man like him preferred.

But it was all he had.

In all honesty, he knew he was likely sending the boy to his death right then and there, but…the odds were better for him in surviving the merciless sea than if he stayed.

But, if this was the end of them, he would make it an end worthy of everything they stood for: defiance and deception.

The boat was long out of sight when he felt heat scorch across his back. "It would have to be you," he muttered, turning slowly to face the man spearheading this…extermination. "Of the three of you, there was only one fit for this kind of mission: killing without question." The man before him was a bull of a specimen. His face set in a grimace befitting one so perpetually angry, a notably odd pairing with his flamboyant wardrobe, a flowery shirt over red slacks, was none other than Sakazuki, or Akainu as he'd come to be called in recent days with his latest promotion. Akainu, the "red dog" of the Marines. A man who had no qualms killing in the name of the government's vaunted "justice".

"You're the leader of this village," Akainu grumbled, visage eternally stony. "By order of the World Government, your people have been found in violation of the law." No list of crimes mentioned, no specifics of violations, just a simple 'You're guilty. Die.'

During which, the likely last remaining Sarutobi had removed and lit the pipe from his pocket, enjoying the small vice. Not like it was going to kill him, right? Still, the old man scoffed before the promise of death looming in front of him. Veiled words were pointless at this stage, so he figured there was no point in blunting his honest opinion, at least as long as he had breath…and could continue to distract him. "The words of a man so blinded by authority that he can see nothing else. Killing us will have gained your leaders nothing. There will always be those who will not bow, and I can assure you that you cannot kill them all."

"Are those your last words, then?"

"…" Taking a last, deep puff of his pipe, savoring the drag, "Good as any I suppose." Ready now, he tossed aside his pipe. He wouldn't be needing it any more.

'Survive, my boy…It's not fair to ask of you, but carry on the Will of Fire.'

Within the hour, the once temperate climate of the islands was ruined. Earth cracked and magma spilled upward, washing over all, until, hours later, all that remained of the isles were massive, slag-covered mounds sticking from the water's surface.

And, all the while, the many naval vessels stood silent vigil, making absolutely certain that their job was done, that nothing remained. Unaware of the precious parcel that'd slipped beyond their sight.

End Prologue

THE PREMISE...

The standard truth was that no-one could eat more than one Devil Fruit. Not without suffering death. Not that there were cases towards either point. Succeeding or dying, no-one had ever even tried, keeping to that taboo.

Though there were several individuals of note who had studied the phenomenon in far greater depth than most. Like the fabled Dr. Vegapunk of the Navy R&D.

The idea:

It is actually possible to eat and obtain the powers of more than one Devil Fruit. Whatever trait that allows this fusion though is so recessive that only one in a hundred thousand or so people might have it. What's more, there was no identifying those individuals, and the rarity of Devil Fruit made it incredibly more difficult to try and study.

Naruto, born on the island of Konoha, one of a series known as the Elemental Chain. Islands known for living on the fringe of World Government rule. Like Amazon Lily, the residents are skilled in Haki. Even using it with elements? (Parents killed by Akainu? (Would certainly drive later meetings.))

Originally ate a kitsu kitsu no mi (fox fox fruit, Zoan) by accident when he was two. Having wandered from his father while in the market, stumbling on an alley dice game and ate a prize, an odd looking fruit. His father rescued him before they could beat him to pieces, but not before he semi-transformed, gaining fox-features.

Quite the cuteness factor with ladies for such a little kid.

At some point later, after the destruction of his home, winds up eating another fruit. Maybe as an accident. After sent away by Hiruzen, shipwrecks on an island and, starving, unknowingly eats a Devil Fruit. Doesn't know until first bite that it is a Devil Fruit. Filled instantly with ungodly agony, energy rolls off him and ghost-fire seeps from his body. He'd eaten the rei rei no mi (spirit spirit fruit, Paramecia.)

(Survived via youth, strong life-force, and sheer stubbornness...and the secret, recessive bloodline trait of his people)

Thus, a secondary being/personality is created within him, a colossal fox creature composed of pure energy.

Eventually, learns what happened to his home. As years pass, he is warned by his "partner" how much his inner anger towards Akainu and the Navy in general is affecting his personality and powers. Resistant at first, is shocked to find how little he cared about the happiness of others when quizzed by Kurama. Spends four years in solitude, taming his rage.

Meets Jiraiya at one point, the latter shocked to find his former student's kid survived the "purge" of the island. Taught his father's haki techniques: rasengan and flash step.

Minato joined the Marines as a way to show they could all get along. Would've eventually revealed that he was an Otsutsuki.

First official chapter starts with a dream sequence, remembering better times as a child. "Old man! Old man!"
Then, jerks awake at the helm of his commandeered ship (sloop – cutter – schooner – brig/brigantine)
The Will of Fire : "The will of my people burns on."

Honestly, the only reason he hadn't capsized at least once already was due to his own naturally high speed and agility. He could be up the rigging and securing the sail in a blur, and instead of climbing back down to go up the second mast he simply jumped across the distance. Still, the ship was not meant to be crewed by one, easily anyway, and it was taxing in its own small ways.

-Or, learned to split off pieces of his energy into copies of himself.

Thoughts of potential crew...

Naruto comes across an island with some recently shipwrecked rookie pirates:
Ur, and her daughter Ultear (haki users)
Juvia, 18 (navigator, aqua aqua fruit)
Natsu, 17 (deckhand/thuggish muscle, fire dragon fruit)
Elfman, 18 (deckhand/muscle)
Lucy, 17, secretly the daughter of a World Noble, having left out of shame towards her family.
Mirajane, 19, and Lisanna, 17 (cooks, demon demon fruit and neko neko fruit)
Erza, 19 (swordswoman), with a small collection of surviving swords.
Wendy, 17 (Adult Wendy from Edolas, scout, sky dragon fruit)

Laki? (amateur shipwright, wood wood fruit)

Used to be a gang of friends who'd all gone to sea together. Lasted six months before shipwrecked.

Naruto x Ur/Ultear/Juvia/Lucy/Mirajane/Lisanna/Erza/Wendy

"Bad dreams, kid?" Leaning back against the small boulder that bordered their campsite, the elder man swirled his mug of morning tea before gulping it.

"It's nothing, ero-sennin."

Not even affected by the nickname, the wild-haired hermit shrugged. "It's nothing to be ashamed of, boy. We all get 'em." The blonde stayed silent. "Though I s'pose they're a little different in your case."

Blue eyes shifted warily towards him, confusion peeking out from behind the aloof exterior.

"Lemme guess…always the same one? A big, strange city, and people throwing around the elements?"

Naruto felt his blood run cold, and although no words came, Jiraiya continued. "You wouldn't be the first to have those dreams. In fact, a rare few people with family from the Elemental Islands would get them. Though…your mother's family got them in almost every generation. They vary, but always revolve around a society sometimes at its height and sometimes being razed."

The one question that scared the boy upon hearing that though, "Then…are they nightmares?"

"Hard to say. I wouldn't call them just anything. There've been a few theories tossed around. An old friend of mine had a theory of her own." A reminiscent smirk tugged at his lips. "She said that it was some kind of blood memory, passed down. 'S why it appeared more often in families that hailed from way back in the history of the Elementals. She claimed…that they were proof of the stories about the Otsutsuki."

"The fairy tale?"

Jiraiya snorted. "Fairy tale or not, the way she rationalized it all certainly explained our people's long standing distance from the World Nobles." An ancient city razed by the World Nobles, for whatever reason, only for the people to scatter to the winds. That some would eventually gather together and form a new home for themselves. A home that would eventually be known as the Elemental Islands.

There was never any proof solid enough to weigh the theory against, but the idea as a whole had always nagged at the back of his mind.