-Grand Line-

-Going Merry-

-Two Days Later-

Once the night after next had fallen it was clear that Naruto and Sasuke's sneaking mission had gone off without a hitch. The two young ninja spent the next day and a half resting and healing while hidden away from the current conflicts centered around the bell. Their Log Pose set just a little bit later than advertised and shortly after that, Naruto was alerted to the approach of the Going Merry after one of his clones disincorporated, sending the memories that that clone had experienced back to the original Naruto on the island.

Even late at night, Sasuke easily spotted the tentatively approaching Merry and signaled them using a simple jutsu designed to produce focused light. The two shinobi were retrieved with no trouble at all. Montblanc Cricket and his Salvagers bid their new acquaintances a fond farewell and left to do some long-term planning about a life that didn't involve golden bells of any kind.

The days after this passed fairly quickly, with a lot of work to do repairing the damage done by the Akatsuki bomber as well as the damage to themselves.

As time moved on, the crew began hearing strange noises across the ship. Sometimes, when Usopp was hammering, it would sound like two people were working instead of one, or there would be odd pounding noises at unusual times of day. At first, Usopp blamed Naruto and his clones, who had been helping out with the repairs. Then, one morning, a newly-healed Usopp woke everyone up to tell them that he had seen a strange figure working with some of his discarded tools at night, but it was soon dismissed as dreams. When all was said and done, the repairs to the ship were completed in excellent time, though the scars of the battle remained quite evident.

After the harrowing experience they had shared, Usopp and Naruto fell into a comfortable friendship. Naruto's self-sacrificial dive to push Usopp out of the way of the explosion, as well as keeping his word when they brought back the Log Pose, did a lot to ease the sniper's earlier mistrust. Strangely enough, it was his shadow clone that had performed a great deal of the initial dialogue between the two of them, so the original Naruto was left with the odd experience of suddenly being aware he had a new friend at the very moment the old shadow clones disappeared.

So it was that four days after leaving the island, Naruto and Usopp sat together working over a single problem: Nami's Clima-Tact.

"She really created a thunderstorm with this thing?" asked Naruto, wonder in his eyes, "How? It doesn't have anything in it that actually does anything, does it?"

Having built the device himself, Usopp had to interject on a point of order. "Ah, but there are parts that do things in here. Look, here's the heat pump that makes hot and cool air from either end. Here's a water reservoir. This device right here generates static-electricity, and then-"

"Yeah, but this is all, you know, really weak, right? No offense, but no seals, or anything to store chakra… how the hell does it work?"

"Well, you see… uhhh… Okay, I'm going to be honest here: I have no idea how she does half of the things she does with this. I mean, I didn't build it to make thunderstorms. Most of this was just for distractions, and then I got a bit carried away and started putting party tricks in there too."

"Party tricks don't summon lightning bolts, man." Naruto turned to look at the distant navigator. "So, how's she doing it?"

Waving Nami over, the two guys found that she was quite willing to explain her methods. The only problem was their own lack of understanding. Eventually giving in to frustration, Nami simplified matters. "Basically it boils down to this: hot and cold air can be used to manipulate air pressure and humidity. With that, you can affect the weather. That's it."

Naruto spun the staff in a single, quick motion. From one end came a ball of vaguely warm-ish air. "You really do all of that with just… you know, this?"

"Yes. It's just an extension of what I do as a navigator. I know no one else here seems to feel the weather like I do, but it's very straightforward, alright?" Nami crossed her arms and shifted her hips, "You can do a lot with just small differences in temperature and electrical charge."

Naruto scratched his head. "Alright, if you say so."

Satisfied, Nami turned to leave. Then, Naruto spoke again. "What if you could do more?"

She stopped. "More?"

"Yeah. If you can do that much with just those little farts of hot air, I kinda wonder what you could do with some actual muscle behind it."

"Whoa, whoa, whoa," interrupted Usopp, "Is this some more ninja bullshit?"

"I guess so," mused Naruto, "I mean, I'm not good with devices like you are, Usopp, but if you had access to a bit of elemental chakra then we might be able to beef this thing up…"

"You want to make me shoot wind and lightning?" asked Nami, raw disbelief dripping from her face, "No way. I don't believe it."

They were interrupted by Sasuke, who had been napping in the corner. "Sorry, but I wouldn't get your hopes up too high, Nami. Naruto, you're reliable in a pinch and all, but scholar of chakra you are not. Frankly, you're a bit of a bonehead."

Naruto tossed a nearby screw, which bounced harmlessly off of his friend's reclining form. "First of all, screw you. Second of all, just watch me."

So Sasuke did watch him. First he was amused, then confusion set in. Eventually, it turned into shock. With a smug expression, Naruto grabbed some small folds of paper from his pack. As he slowly drew his finger across one of them it was if he were drawing a picture in ink, symbols appearing from his careful motions as if by magic. Activating his Sharingan, Sasuke watched the chakra pulse outward through his friend's hand.

"Jiraiya taught you this?" Sasuke asked, fascinated by the display of technical skill from his friend.

"Kinda… More like he pointed me in the right direction."

"What's that supposed to mean?"

Naruto spoke as he continued to work. "So, I'm an Uzumaki, right? Apparently the Uzumaki Clan used to be really, freakishly good at seals of all sorts. That's where the seal on my chest comes from. Jiraiya had the bright idea of hunting down some of the old Uzumaki techniques, which was pretty hard, ya know…" he grinned. "Apparently I'm a natural at it!"

Sasuke was stunned. "I- I don't know what to say. You didn't know that until last year? Wow, finding that out must have been…"

"Huh? Must have been what?"

"I mean, I'm trying to imagine what it would be like if no one had ever been around to explain why the Sharingan was so important for me, or what it means to be an Uchiha fire user. It's just… strange to think about."

Naruto was silent, seeming to take that in. Eventually, he finished his work. With one hand placed on the seal, Sasuke watched him transform his chakra into wind-natured energy and pour it into the seal.

"Alright, it's finished!"

Nami, Usopp, and Sasuke watched with uncertainty as Naruto placed the paper seal on the deck. The blond ninja picked up a small craft hammer and sat down beside it. "This seal is kinda based off of some of the physically-activated varieties you might see in generic traps and stuff, ya know? If you give it a tap, like this-"

Naruto smacked the hammer into the seal, dead center, and a blast of the unusual cutting wind came spraying out of the seal. It expended itself in one violent burst of energy, about four or five seconds long, then went out.

Everyone else's jaws dropped. Naruto grinned, happy at the reaction.

"Hell yes! See?! See what I mean? That's just the start, too. I can tune it to whatever we want."

Usopp examined the seal with great interest. "Huhhhhh…. Well isn't that something… Even if we just stuck with the hammer idea, we could take a few of these on a roll and make a sort of popgun wind-cannon… Just press a button and 'kablooie!'"

"It's not anywhere near as powerful as what Sasuke and I can do with our jutsu," said Naruto, "but I figure if you can make thunderstorms with just hot and cold air then who knows what you can do with this, right?"

Nami considered this carefully. "That's one hell of an upgrade. I'd sure feel a lot safer with something that could do that in reserve... Can you use this 'chakra' stuff to make the heat, cold, and electricity functions any stronger?"

Naruto paused for a moment, then looked to Sasuke. "Well, I can do it as long as we have the right elements…"

When the others looked puzzled, Sasuke stepped in. "What he means is that we only have so much available to us. Every person has a natural affinity with a specific element of chakra. With some training, some people can get two or maybe three. Any more is impossible for anyone except really legendary figures. Naruto's, obviously, is wind. I can use fire and lightning, and can fake certain other elements weakly if I've watched someone perform them, but can't control them naturally. So we've got heat and electricity covered."

"Wind, fire, lightning, but you can't do cold?"

"Cold's not really an element..." said Naruto. "Well, it kinda is, but..."

"Let's just stick with that," agreed Sasuke, "Cold isn't an element we can use, no."

Nami looked a bit disappointed.

Still staring with fascination between the staff and the experimental seal, Usopp offered his opinion. "I don't think that has to be a problem, actually. The limiting factor of the heat pump was power, which is why you have to spin it so fast. If there's a little bit of lightning to work with as power, then I bet I could make something that handles the cold well enough... We'll have to dial down your crazy fire a fair bit to match, though..."

Usopp was in his element. As he worked, someone else started to express interest.

"Umm… Pardon me," came a voice from the upper deck. Chopper was peeking uncertainly over the side. "I've been watching for a little while… When you said 'every person' has chakra, do you mean just you ninjas?"

Naruto grinned back at the curious reindeer. "Nope! I mean everyone! You too!"

"Really? How can you tell?"

"Well, for example…" Naruto poked the top of his head and twirled it in his blond hair. "You can tell what direction your chakra swirls around inside you by looking at the way your hair swirls on your head! And that means…"

Suddenly, a second grinning Naruto ambushed the reindeer from behind, grabbing his pink hat with both hands. As Chopper screamed and squirmed, Naruto pulled the hat off from around his antlers with a *POP*.

"Look at that! If I mess up your fuzz then your chakra's gonna go all over the place!"

"AHH! STOP IT! STOP IT YOU JERK!" Chopper squealed, trying desperately to wrest away from Naruto's fuzzing grip. Finally, he transformed, growing nearly six feet in a single instant. "I SAID STOP IT!" The Naruto clone was tossed into the air, hitting the lower deck in a heap before exploding into a puff of smoke. Before anyone could say anything, Chopper ran off.

There was lots of laughter from the lower deck, Naruto's loudest of all.

As Sasuke stopped chuckling, he decided to give the little guy what he wanted. He called out, "To answer your question, Chopper, we have a test we give to people to see what kind of chakra they have. We use a certain type of paper that's made from trees that are fed chakra as they grow up, but I'm sorry to say that we didn't bring any along with us."

"Nah, it's okay," said Naruto, tearing bits off of a piece of the paper he had used to write the seals, "'cause all the best paper that's used for sealing is made of the same stuff. And the Uzumaki Clan only uses the best." Smiling, Naruto held out a fan of several roughly torn patches of paper. "I'm thinking we should try it out."

Naruto's enthusiasm was perhaps a little bit hasty. Chopper was watching them suspiciously from behind one of Nami's tangerine trees and refused to come out, so only Nami and Usopp were nearby, and both of them failed to generate any response. Sasuke assured them that this was normal for anyone that hadn't trained to control their chakra. Still, a bit of searching the ship led them to bring Zoro, Sanji, and Luffy back to the deck.

"What is this? What do I do?" asked Luffy, holding the paper in one hand.

"Well, you just focus your chakra-" started Naruto, before frowning uncertainly, "Uh, that is, you… just concentrate on the paper… and think about the energy you… Hmm… I don't know how to explain this to you. Focus on it, and do what seems natural."

"Oh, so it's mystery paper. Got it." said Luffy.

Luffy stared at the paper for a moment, then gripped it while clenching his teeth and making odd grunting noises. Eventually, he popped the crumpled up paper in his mouth.

"What the hell?" asked Naruto.

"I don't think your paper works," said Luffy, before wandering off, bored out of his mind.

Zoro proved a bit more cooperative. His chaotic-looking chakra, as well as Sanji's, actually reminded Sasuke a bit of an older Chuunin in their village named Rock Lee, but it was hard to tell if that was a coincidence or not. After holding the paper and concentrating thoughtfully for a moment, Zoro shook his head. "Don't think so," he said.

Sanji laughed. "Yeah, I thought not. If that chakra stuff needs strength of mind as well as just plain strength, then you're screwed."

Naruto was undeterred. "Try… I dunno. Try imagining like that paper's one of your swords and you're about to swing- Whoa!"

In the middle of his sentence, the scrap of paper in Zoro's hand cut in half and fell to the ground.

"Nice!" shouted Naruto, as Sanji groused, "That means you're wind element, like me." He held up his fist, and Zoro solemnly fist-bumped it.

"I suppose we kind of guessed that already," said Sasuke, "What with you shooting sword wind-blasts and everything. Sanji? Want to try?"

Desperate to show up his rival, Sanji stepped up immediately, grabbing the proffered slip of paper. Focusing with all of his might, the paper was not affected in the slightest. Grumbling and grunting, he pushed harder, before Zoro started to chuckle.

"Too much for you, you dumbass cook?"

Sanji let out a heavy breath, relaxing for a moment. After another try failed to generate a response, he cursed. "Dammit. This chakra stuff, I thought you use it to walk on water, right? Why am I using my hands for this?"

Naruto shrugged. "It's just generally the easiest way to do it, you know?" he said. "But most ninja can use their feet too, obviously. Only someone like a Hyuuga can shoot a lot of chakra out of anywhere else, though."

"Well, hell if I'm gonna stick to my hands, then," Sanji grumbled. Slipping out of his reinforced dress shoes, he dropped the slip of paper on the ground. Stepping on it with one bare foot, he laughed as the paper suddenly burst into flames.

"HAH! In your FACE!" he cried out, triumphant. "Okay, so I guess that means I'm fire?"

"Yeah," said Sasuke, "Just like me. I still don't know what you'll be able to do with it, but knowing that is a start.

"Umm…" spoke another voice from the upper deck. Chopper was once again peeking over the side. "If you don't try and grab me again, I'll try it…"

Naruto grinned. Before long, they coaxed him down.

"Alright," said Naruto, "You're smart, so I bet you'll understand this. Look deep inside yourself, right inside your fuzzy little belly, and imagine the energy that fills you. Imagine it travelling up through your body and down into your arms. When it gets down to your hands- er, hooves- push it out into the paper."

As Naruto spoke, Chopper concentrated with every fiber of his being. He could feel what Naruto was saying. It was a little bit like how his body felt when he was using the Rumble Ball. Now that he tried it, it was like he could move that energy about just by thinking about it. Up into his chest, down his arms, and into the…

The scrap of paper in Chopper's hooves shook gently and sprouted a tiny greenish-white shoot. As he watched, a single leaf popped out from the growth with a cute little *POIT* sound. Chopper's eyes went wide, and his jaw dropped open.

"I- I did it! I made it grow! I made it grow! That's incredible!" He laughed and hopped excitedly in place, then turned to the two ninja boys. "What does that mean? What am I?"

Naruto was just frowning and blinking at him. "Uhh… I don't… what?"

Sasuke looked like he'd just seen a ghost. His jaw was hanging wide open and he had stopped breathing or blinking.

"Oh no!" cried Chopper, "It's bad?!"

Sasuke shook himself, glanced at Naruto, and then shook his head again. "No… it's not… It's fine… just… Naruto, could we have that last piece of paper?"

Calmly, Sasuke handed the paper to Chopper. "Chopper, if you don't mind, I'd like to watch you with my special eyes when you do that. Is that alright?"

When Chopper had no objections, Sasuke activated his Sharingan, red eyes swirling into place. He could see the path of Chopper's chakra, burning and pulsating inside him. The chakra coils in his abdomen were filling the young reindeer with energy. It looked hungry and excited, like a beast just waking up from a long hibernation.

When Chopper made the paper sprout again, Sasuke was certain. Something incredible had just happened.

"Chopper, you're amazing! Your energy is unbelievable. I hardly ever see anyone with physical energy as strong as yours. You might even have more than… well, Naruto. It's practically inhuman."

Chopper wasn't sure whether to blush or frown at the odd compliment. "Well, I'm not a human," he said.

"What?" asked Sasuke, looking up in surprise.

"I'm not a human! I'm a reindeer. I just ate a Devil Fruit that made me partly into a human."

Sasuke blinked, swallowing down a surprised lump in his throat. "I… see… I guess that makes sense. I had thought it was the other way around… That means your baseline body is an animal, so of course you'd have the incredible physical energy of a beast. All you'd need is mental energy..."

Soon, Sasuke started tracing the lines of Chopper's chakra. All of the paths were exquisitely perfect, as if they had been sculpted from an ideal. There was almost no resistance at all. It was surprising he wasn't shooting chakra out of his pores at all times of the day. Sasuke could see tiny trickles of Earth chakra and Water chakra both flowing through the boy at the same time, but he doubted that any element would be out of the reindeer's reach with proper training. The ability to use wood-element ninjutsu had been lost to humanity since the First Hokage had died, but apparently Mother Nature had decided that reindeer needed it more than humans did.

Still, there was something weird about it all, beyond even the incredibly perfect chakra system. There was a hint of something else. Soon, he realized what it was. It was as if there was a second source dumping energy directly into Chopper's system at each one of his chakra points.

Each of them looked almost like Naruto's seal that drew energy from the Kyuubi, to be honest.

"The other component of chakra is mental energy…" Sasuke mused. "If you don't have enough of that, you can't take advantage of your body's natural physical energy. I would have guessed that as an animal your mental energy would be weak, but…"

"Hey! I heard that!" shouted Chopper.

"Chopper, pardon me for a moment. I'd like to take a closer look, but I need to look into your eyes for a little bit to do it. Is that okay?"

After a moment, Chopper relented, nodding his assent.

Over the course of his training, Kakashi had given Sasuke some tips on controlling the chakra of the tailed beasts using the Sharingan. It was a purely theoretical exercise, as Kakashi knew that it was only a possibility if he were to use his brother's Mangekyou Sharingan, which at that time he hadn't had access to.

When Itachi had met with Sasuke inside the Tsukuyomi, his brother had been quick to offer Sasuke even more information on that subject, once he had learned that Sasuke was best friends with the Kyuubi's host. According to Itachi and Kakashi both, the Mangekyou Sharingan was known to have some minor ability to suppress and control malicious energies, like Naruto's Kyuubi. That was, in fact, the reason that the village mistrust of the Uchiha had spiked after the Kyuubi had attacked the village all those years ago.

He had also been warned that attempting to suppress the Kyuubi in actual combat would be a fatal mistake; it was something to be attempted only if the need was truly dire.

He focused his chakra, the Mangekyou Sharingan blossoming in his eye. He wouldn't use the Tsukuyomi; He'd just use Itachi's Mangekyou to make a connection the same way he might start any other ocular genjutsu. If there was something dangerous about these Devil Fruits, his eye might protect him.

Staring into the nervous young reindeer's eyes, his awareness of Chopper disappeared. Moving into his chakra system through the brain, it was clear that his mental energy was nearly as well developed as his physical energy. Or perhaps it was more.. potential? He had great potential in both areas, which was highly unusual. Perhaps the Devil Fruit that had given him a human brain had also given him an idealized system of mental pathways?

Sasuke dove deeper and deeper into the well of the boy's energy, finding one of the tiny portals that were generating the mystery-chakra and watching it as he grew closer. It really was different from a normal person's, and also different from Naruto's. This wasn't a seal; it was more like a... symbiosis? He looked closer and closer, the flow of the chakra changing color in his sight as he stepped inside...

A human stood before him, built entirely of green fire. The human's black, empty eyes gazed back at him, filling him with an existential dread. How could something with no eyes even see? It was wrong. The creature's proportions were off, its limbs slightly too long. He could feel its chakra washing over him, and every drop of it was written with a deep intelligence that made him feel so unbearably small. It was so old, and this creature knew exactly how young the child that had wandered into its lair really was. It knew everything about him. It knew everything he was, and everything he could ever be. Slowly, it opened its dark, abyssal mouth and began to speak.

"AH!" shouted Sasuke, falling backward in shock as he broke the link.

Having been staring right into Sasuke's eyes for the last minute, Chopper screamed as well, falling over backwards and scrambling away to safety.

Naruto was with them both in a second. "What the hell, man? What was that?"

Sasuke took a moment to calm down.

"I guess I learned two things," said Sasuke. "First, Chopper, you've got Wood-element chakra, so congratulations on being one hell of a reindeer. Second, I think I just saw your Devil Fruit-" He turned to Naruto, "-and I think it's just like a tiny version of the Kyuubi."

A/N: This is not a story where all the pirates become ninjas and all the ninjas become pirates. In general, learning ninjutsu takes many years of practice. Still, Nami needed something to replace the Dials, and I am going somewhere with this, so trust me if you can.

I have pushed back the date of the Void Century a little bit to facilitate the story. I don't think this will present a problem.