Naruto curled deeper into Kurama's fur.

"..."

Kurama looked at the traumatized child clutching at his pelt. It had been this way for the past month ever since Naruto had lost his eyesight to Black Zetsu's plan.

"Brat."

"..."

"Brat, if you don't start taking me seriously, then I can't help you."

"...what will it even do? I can barely move around. It's so hard to eat and I have to rely on Karin and Tobi for help…" Naruto whimpered.

"You said they exchanged your eyes with an Uchiha. The Sharingan is a powerful eye. It needs a suitable vessel that can support it. Your body needs to become strong."

At least, that's what Kurama assumed. He didn't know a thing about human physiology.

"…how do I become strong?"

"Weren't you training with that man Tobi? You were getting stronger the more you practiced ninjutsu."

Naruto had stopped training in the past month after he became depressed. Tobi's attempts at cheering him up weren't effective.

"You want me to continue…?"

"How else will you get stronger? I can't train you if you won't even try."

"You…you can train me?"

"My power is stronger than that little Sharingan. If you can't even grow strong enough to adjust to it, then how will I teach you how to use mine?"

"What can your power do?"

"Heh, I won't tell you until you get strong enough brat. Just know I can destroy entire mountains with just one jutsu."

Kurama's smirk drew Naruto's attention.

"How…how can I become strong enough?"

"Continue your lessons with Tobi tomorrow. Now, we begin training here."

=== GEDO MAZO CAVE ===

Something was different.

Karin watched as the blonde her age dug into the breakfast White Zetsu stole for them. The atmosphere around the boy had changed compared to before.

"Wow! Did something happen to you or what?" Tobi weakly joked as Naruto scarfed down the food. The blonde paused and looked at him before returning to his meal.

Karin stayed silent. She was still scared of her captors. It didn't help that she was inside a strange cave with the large statue for about a month now. Luckily for her, only the cheerful one remained with them.

When the meal was finished, Naruto approached Tobi.

"Can…can I still learn ninjutsu? I know I can't read anymore but I can still learn the hand signs at least…" He asked while twiddling his thumbs.

"OF COURSE!" Tobi jumped up excitedly and ran to get the ninjutsu scrolls. "Let's continue your morning routine! Begin with the big techniques until your chakra pool is low enough to cast small ones, then we can work on your chakra control or a new jutsu!"

Karin blinked.

They…were teaching him?

But then…why did they take his eyes? It would be more difficult to learn without them.

Karin blinked when Naruto began flashing through hand seals.

Wait- his chakra!

Her unique sensory abilities were some of the most sophisticated in Kusagakure. So when Naruto started manipulating his ocean of chakra, Karin was able to feel the change in the air.

Monsters.

They were all monsters.

Not just the trio of humanoids, not just the man whose chakra who scared her, but also the boy her age they were taking care of.

Karin gaped as the ocean moved to answer Naruto's call.

Then, she was promptly blasted in the face with a breeze as the B-rank wind ninjutsu filled the cave.

…

"Sorry. I forgot you were here." Naruto bowed as he apologized to the girl.

He had honestly forgotten that they had kidnapped another child to help him and Tobi recover.

Karin leaned away nervously from him. He was nothing remotely close to the other children she saw. Not even the jounin of Kusagakure had as much chakra as he did when he decided to use it.

How had she missed it?

No, she hadn't. It was just that seeing him so inactive made his chakra static and unresponsive. Seeing it in action was a whole different thing.

"I-its…fine." Karin forced out.

"I'm sorry…what was your name? I forgot. Mine's Naruto." The blonde reached out a hand.

"K-Karin."

Just like that, Naruto made his first friend.

…

The next morning, White Zetsu dropped by with a new batch of scrolls.

"Look! Look! Naruto's back to normal!" Tobi excitedly showed to him.

White Zetsu took one glance at Naruto going through his morning routine.

"I see." He handed the scrolls to Tobi. "Tobi wants you to also teach the girl medic ninjutsu. Her chakra is perfect for it."

"She doesn't look comfortable around us though."

"I don't care. Teach her."

White Zetsu disappeared into the ground and returned to his duties.

A few days later, Obito returned. Naruto didn't like the idea of approaching him, but Kurama insisted that he learn how to fight. The only way he was going to do that was by asking for lessons. Tobi couldn't teach Naruto how to fight because he wasn't any good at it.

That left Obito as Naruto's only choice.

The Uchiha looked up as he stopped in front of him.

"I want to learn how to fight."

Naruto felt Obito's gaze on him.

"I won't hold back just because you're blind."

That was the problem, wasn't it? Naruto would have to learn how to fight blind.

Luckily for him, Kurama had been teaching Naruto how to sense chakra. As an entity that was formed from chakra, he had the know-how and experience to impart some of his lessons.

"Okay."

Obito raised an eyebrow. He had heard from White Zetsu that Naruto had recovered from his depressed slump a few days prior. Seeing the determined boy in front of him was a complete turnaround compared to the wreck he was a week prior.

"I can't teach you much outside of the basics and a little more. It will be up to you to develop in the future how you want to fight."

Before Obito left the Hidden Leaf, he had learned some of the Uchiha's style and preferences when it came to fighting. The academy lessons he was taught helped round him out enough to survive in the 3rd Great Shinobi War.

"Teach me whatever you can please." Naruto asked.

Tobi stood up.

"Then…let's begin with your stance."

One year later.

She was supposed to learn how to be a healer. Instead, here she was trading blows against her opponent.

7-year-old Karin Uzumaki moved around with as little noise as possible to avoid informing her opponent of her position. She stalked around and positioned behind before she launched her assault.

Just like before, Naruto reacted like it didn't matter. He twisted around and met her fists with his palms, redirecting them while trying to sneak his own retaliation underneath the flurry of blows they exchanged.

Left, right, up, right, left, up, down.

Karin attempted to slip her foot between his legs and twist it around the right foot to throw his balance off, only to fail when Naruto reacted with a kick once her foot landed on the space between his legs. Her arms swung up to block the kick, then threw a leftie which he blocked. The defense weakened due to his unbalanced position and Karin was able to capitalize with a palm strike to his stomach.

"Guh-" Naruto grunted as he retreated. "I shouldn't have went for the kick."

"You're too eager at counterattacking."

"It's my best chance! It's harder to be on the attack when you're blind."

"Well stop overextending so much. You can throw shorter counterattacks with your elbows and knees, right?" Karin pointed out. "Now, what about me? I tried further this time to avoid alerting you with my foot's vibrations. How did you know where I was coming from?"

"It was your clothes. I heard them flapping."

"You can even hear that?!"

"I can hear and feel everything better."

Naruto and Karin continued to go over their last spar, searching for ways to improve.

Such was life for the two friends in the past year. With nothing to do, Karin slowly got dragged into Tobi and Naruto's lessons. Obito wasn't always around, so Naruto asked Karin if she wanted to become his sparring partner. Karin agreed since it was something to pass the time.

"Psst! Naruto! Karin!"

The two children looked at Tobi popping halfway out of the ground.

"I've got some good news for you two!"

They perked up. Good news? They haven't heard anything good from Tobi in the past year. Usually, that was because he couldn't get permission from Obito or either of the Zetsus.

"We finally have permission to bring you to a village!"

Karin blinked. After one year of being stuck in a cave or brought outside for some sunshine close by, Tobi was finally bringing them somewhere new. She snuck a look at Naruto who looked more than ecstatic. She could understand why. Naruto had never been to one. His knowledge of what a village and life outside the cave came from her stories. It was quite sad to consider that her friend had essentially been locked away in this cave all his life.

So, she couldn't understand how Naruto stayed bright and positive all this time.

The worst she had seen him was when the boy lost his vision a year ago. Even then, he bounced back quickly for someone who learned that he might live the rest of his life without eyesight. Not unless his old ones were returned or a new pair of eyes were given.

Karin still couldn't believe these people gave Naruto's eyes to Obito. She didn't understand why.

"A village? We're going out?" Naruto asked excitedly.

"Yeah!"

"A real ninja village?!" Naruto jumped up.

"Probably not. Just some regular village out there." Karin explained.

"No, it's too dangerous to bring both of you to a ninja village." Tobi clarified. "Obito would kill me if he heard Naruto getting in range of any."

Mostly because they would probably kill him if Naruto got captured and Obito's Mangekyou Sharingan taken.

"Oh."

…

The village Tobi brought them to was far more interesting than Karin would admit. It was located beside the coast. The small port extended out into the beautiful crescent cove that protected the cape inland. The view was beautiful and Karin fell in love with the sight from her position on top of the trees.

"Is this how the sea smells like?"

Of course, Naruto couldn't see any of that. That didn't stop him from picking up on everything else far better than Karin could.

"We're a few kilometers away and you can smell the ocean?"

"…I can?"

"Naruto, what else can you smell?" Tobi asked. Naruto's senses were becoming the best out of their bunch. The next best would be Karin, but that was because she had some sort of instinctive ability to sense chakra on a level none of the others could reach.

"I smell…" Naruto's nose visibly twitched as he sniffed the air around him. "-a lot of food."

Tobi grinned.

"That's right! This small village is hosting a food festival! Are you both excited?!"

Naruto's face bloomed into a grin. Even without his eyes, the crinkle around them showed just how excited he was.

"FOOD!"

"So that's why you brought us here." Karin smiled. She was also looking forward to the idea. A food festival! She had never been to one.

Naruto was already shimmering his way down the tree with speed people wouldn't expect from someone without sight. Karin followed him down while Tobi just leapt off the top and landed on the ground. Once the two reached him, they headed off for the village.

…

Naruto's mouth drooled as his world was filled with scent. The trio walked down the street surrounded by food stalls and carts by visiting merchants. People from other villages also came to enjoy the event.

"Naruto."

'Yeah, yeah, Kurama. I can tell.'

One year of training with Kurama in his mindscape had a different set of results compared to Naruto's physical training with Tobi and Karin. Besides Kurama's horrible attempts at teaching the kid, mostly it being his first time teaching combined with a different circumstance, one being an elemental force of nature and the other a human child, Naruto was able to pick up on how Kurama sensed chakra and negative intentions. While not on the same level as Karin, Naruto could in a sense 'see' chakra in different hues after a year of learning under the bijuu.

"Tobi, there's some ninjas here." Karin warned their guardian.

Looks like Naruto didn't have to warn either of them now.

Tobi quickly nudged their group to one of the food stalls on the side. Naruto did what any normal person would've done in that situation.

Look at the food like a normal customer.

He forced his attention away from the chakra signature and started observing the food choices in front of him. Not that he could observe any of them. Naruto was relying on his sense of smell to locate and identify what they were.

Boy was he bad at holding his nerves.

Gulp.

"K-Karin? Can you tell me what the food in front of me are? I-I can't see." He stuttered his words.

Karin caught on quickly and played along.

"Uhh…dango, mochi-" She continued to enumerate the menu and the food being cooked by the chef.

"H-have you ever tasted these before? What do they taste like?"

Naruto was pushing the rock along with their impromptu act as the chakra signature walked down the street. They were very close. Just a few meters away from their group and situated in the middle of the street.

"They're mostly desserts. They should be sweet unless they have a specific flavor they are going after…"

Tobi kept silent as they spoke. Fortunately for them, the ninja walked past them as if they weren't there. Naruto and Karin released a sigh of relief as the danger passed.

"So-" Their guardian clapped his hands together. "What would you two like to order?"

"Uhh…Karin what would you suggest?" Naruto asked the older girl.

"I'll just go with dango." The girl murmured, still unnerved by their run in with a ninja. Her experience with ninjas weren't exactly good because of the fact most if not all of them took advantage of her. Including Obito and the Zetsus. Karin knew that despite the change of her environment and Tobi's kind treatment, she was still being used like an object by her new owners.

She wasn't the only one. Unlike before, she wasn't lonely now. She made a new friend in Naruto, who was just like her. A tool also being used by them. Compared to everyone in the past, at least Tobi and Naruto were honest to her.

"How about you, Naruto?" Tobi turned his head to look at him.

"I think I'll try dango too…"

Tobi pulled out a wallet and ordered the snacks for them. Their dango was handed over and they returned to exploring the street full of food.

…

When it was late afternoon, Tobi didn't bring them back.

"Tobi? Isn't it getting late?" Naruto asked as the sun set over the horizon. Warm afternoon air was slowly beginning to leave, replaced by a cool evening breeze as the streets lit up lamps to continue into the night. The trip back would take hours, long past dinner time if they started now.

Tobi stayed quiet.

Karin's instincts tingled. Something wasn't right.

"Do you remember the ninja from this morning?" Tobi asked.

Naruto pressed his lips together nervously. Just what was going on?

"…yeah? What about him?"

"Tobi has a mission for you two."

For some reason, he didn't like the sound of that.

"What mission? We're just kids." Karin asked. "We don't even know what we're going to do-"

"Kill him."

Her voice died off as Tobi uttered those words.

"W-what…?" Naruto whispered with horror.

"Your mission is to kill him." Tobi repeated.

"He can't be serious…" Karin murmured. "We're just kids-"

"Tobi wants the both of you to start learning how to help around."

"H-help around…?" Naruto's voice shook. He and Karin knew exactly what Obito and the others did. Obito would return to the cave many times drenched in blood, sometimes he would be wounded, more often not.

They weren't good people. Not in the slightest.

"We don't even know how to kill him! We don't have weapons!" Karin swallowed the lump on her throat.

"You don't need a weapon for this." Tobi knelt in front of the two kids. "I know it might be hard…but you can do it! This man is wanted. He has done a lot of bad things." He pulled out a small leaflet and showed it.

Sure enough, Karin saw the man's information. A C-rank shinobi unaffiliated with any village. The nearby villages put out a small bounty on his head, just barely above that of random gangs and mercenaries that pulled robberies on civilians on the road. His threat and bounty level were small enough that even shinobi and bounty hunters ignored him.

"See? We're not making you do anything bad!"

Yet.

Karin and Naruto knew that it was only a matter of time before they would be sent after other targets. Obito and the others had that sense about them that screamed danger. It was impossible to ignore for the two capable sensors. Naruto and Karin may have gotten used to it, but they knew that it was only directed to others.

"And if we don't agree?" Karin gulped.

"Well…they didn't tell me what would happen."

Of course they wouldn't. Tobi would try to protect them, but he would fail.

Karin faced her friend. Even Naruto's face was pale. They had an idea what failure meant.

If not death, then punishment. They'd be forced to do something worse down the line.

"O-okay. We'll do it…"

…

Tracking down a target in a crowded village was a completely new experience for Karin and Naruto. It was different from learning ninjutsu and sparring. Fortunately for them, they had the ability to sense chakra which proved useful.

"Hoo? Are you two sure he's staying in that inn?" Tobi asked while peering at the small building at the edge of town.

"Yes. He's the only one with a remarkable chakra signature." Naruto explained. "Nobody else in the village has chakra as developed as his."

The rest of the villagers had a dull color because they didn't train. The man's signature was stronger and denser than the rest.

"So? What's your plan now?"

Karin and Naruto exchanged looks. They hadn't really planned how to get in close.

"Can we ask to enter from the front?" Naruto tilted his head hesitantly. This was his first time approaching a problem of this sort. No ninja experience or lessons in tacking objectives had been touched this far in his training.

In a way, this was his first lesson.

"I-I don't think they'll let us in unless we pay for a room." Karin realized. "Tobi…we can't rent a room can we?"

"Nope. That's not how ninjas do it." He cut off that avenue.

"We…sneak through the window? It's the only other route." Karin looked at the room their target was in. "His room doesn't have a window, but we can use the corridor."

Their target picked a safer option by choosing a room that didn't have a second entrance point.

"Okay, so sneaking in is your best option. How would you deal with the locked door?" Tobi pointed out another problem. He was smiling at how the two were slowly approaching each problem given to them.

He was just going to have to nudge them until they picked up the answer on their own.

"Uhhh…break it?" Naruto suggested.

"Break it. With your fists?" Tobi questioned.

"Ninjutsu." Karin offered.

"Okay, do you have anything that can break a door lock quietly?"

Actually, they did.

Karin was talented in water and earth ninjutsu. She had better chakra control than Naruto due to her smaller reserves, which allowed her to learn smaller techniques.

"I can use Water Palm Blade to cut the lock." Karin said.

"Great idea!" Tobi clapped. "Now, how do you plan to kill him? Let's imagine he is awake. He knows you're coming for him. You'd probably have to fight. Are you going to keep it silent or will you blow up the room with him?"

Between the two of them, Naruto's techniques were difficult for operations like this. If he used any technique, the entire inn would learn about the assassination right away. Naruto and Karin would be found out, but they could still escape. They'd like to avoid that if they could.

"Uhh…I guess we'd just have to fight him quietly." Naruto relented. They didn't really have any option in that case.

"Right. Sometimes, you can't really do anything else. The worst case scenario is still something you have to plan for." Tobi used a teacher's pose to highlight the lesson.

"Are we…strong enough?" Karin asked.

"He's C-rank at best. The two of you are stronger than D-ranks. As long as you work together, you should be able to fight him. The ability to kill him is down to you. I believe that you both can do it!" Tobi patted them both on the head.

His words of encouragement slightly helped, but didn't really change the moral outlook of the two. They were still doing something evil, even if it meant helping others.

Tobi flashed them a proud thumbs up as the two slowly snuck towards the building from their hiding spot in the treeline. Karin leapt up the wall first, followed by Naruto as they crept their way towards the open window at the back. The floor creaked as the two stepped inside the empty room, causing them to freeze and panic at the sound. It wasn't loud, but the risk of being heard was paramount to the success of their mission.

When nothing happened, the two continued on and snuck into the hallway between the rooms. Nobody else was up, since they chose to wait until midnight for the assassination.

Karin stopped in front of the door and whispered the technique while flashing through the handsigns.

'Wait, Karin!' Naruto hissed without voicing it out.

'What?!' She mouthed back when he grabbed her hands.

Naruto moved to another position and mimed a blade of water cutting through the door from a different angle, an angle that would hit their target behind it. They didn't know if he was awake or not, but the chance that he was prepared was too great to ignore.

He was suggesting they begin the assassination with an attack from behind the door!

Karin blinked as the ingenuity of the idea registered on her.

If the ninja on the other side was awake, he'd expect them to try and sneak into the room to kill him. But if they started the fight before he saw them, then the advantage would go in their favor.

She crept over to his side while Naruto switched to the opposite side of the door.

Karin restarted her technique.

"Suiton: Suishōjin! [Water Release: Water Palm Blade]!"

The attack made little sound as a thin but long blade of water cut through the door's handle quietly. It disappeared into the room a moment before Naruto shoved the door open and jumped in.

"W-whaaaphhhfft?" A gurgling sound came from the man on the bed, cleanly cut in half as the upper half of his chest was separated from his body. He was still lying on the bed, clutching on his serrated chest. The situation hasn't dawned on him, his face confused at the pain he awoke to while looking at the two children staring at him in horror from the doorway.

"Y-you…urk-" He choked as blood spilled out of his mouth. The bloody scene of his chest's innards sliding out of the large gap between his upper and lower chest dawned on him when he saw his half-sliced lung drop on the floor with a splat.

The sound was enough for something to crack inside Naruto as the full weight of their actions settled on his mind.

For the first time in over a year, vision returned to the blind boy.

Naruto's eye automatically locked on to the red organ that came from the man's insides and felt his stomach upend itself. Karin held her shaking fingers up to her mouth in a silent scream as she watched the man's eyes dim from the loss of his brain's connection to the blood being pumped from his heart. They could vaguely see the still-beating heart pumping blood inside the chest cavity, supplying the rest of his body with blood in its dying moments.

It also supplied the pool of blood that was quickly beginning to spread on the scene.

Naruto grabbed her hand and jerked her back while the vomit crawled up his stomach. The only thing his mind registered in panic was to run away from the crime. They forgot to stay silent as they ran through the hallway and jumped out the window they came from. The guests in the rooms awoke to the sound of their escape and opened their doors to inspect the noise.

Luckily for them, Naruto and Karin were sprinting halfway to the treeline as they held their vomit before they could make it to safety. Shouts and screams erupted behind them as the civilians spotted the crime scene.

They stumbled into the treeline and kept running, going past Tobi who followed them.

"Hey! How did it go-" He paused when Naruto stumbled and dropped to his knees, throwing up his dinner on the forest floor. Karin followed shortly after, supporting herself on a tree as she puked.

For some reason, Tobi spotted drops of blood mixed in the pool of vomit coming from Naruto.

"Naruto? Did he get to you?" He instantly jumped beside the boy and worriedly looked him over as Naruto kept vomiting.

His right eye was bleeding.

"Naruto…?"

He finished throwing up, still hunched over on the floor.

"T-Tobi…" Tears and blood poured out of the right eye Naruto was looking at him with.

The eye was shaking, but Tobi saw the Mangekyou Sharingan lock on him. It was bleeding, but it seemed that Naruto didn't notice. Not even Naruto paid any attention to the pain, or the fact that he was suddenly seeing Tobi's familiar face after a year of blindness.

"It…his body…in half…" Naruto choked. He couldn't purge the image of the man's mauled intestines. The blood, the heart, his expression as he choked to death. The horror was traumatizing enough that Naruto was still seeing the man's face as he died.

Behind them, Karin collapsed a few meters away from her own pool of vomit, lying down on the ground and covering her eyes as she cried.

Tobi spent hours comforting the two children as they sobbed the horror away.

.

.

.

"Naruto, open your eyes."

Naruto whimpered as he opened Obito's right eye. Black Zetsu stared at the evolved Sharingan that met his gaze. Searing pain instantly stabbed the blonde in the head and he closed it instantly after a moment.

"You can see?"

"I-it hurts…I can't use it." Naruto choked out while holding both hands over his right eye socket. The powerful eye was unbearable to open. Being blind was better than whatever pain was shoved into his head whenever he used it.

"So…the eye works again?" Obito asked from his position on the rock nearby.

"Yes. It seems that Naruto has unlocked your Mangekyou."

"Then what's the problem?" Tobi perked up from behind them. "Why can't Naruto use the eye?"

"It seems that the Mangekyou requires adjusting to. The same way Obito suffered when he unlocked it."

"So you're saying that Naruto needs to train it?" White Zetsu clarified.

"Yes. This is Naruto's first time using the Sharingan, much less the evolved Mangekyou. I have reason to believe that the powerful eye combined with information overload is what is causing the problems."

"Well, we did just shove Obito's Mangekyou into Naruto. It took him a long time to adjust to it, and that's with him living for years with the Sharingan." White Zetsu looked over to the Uchiha.

"How do we revert the Mangekyou back into the Sharingan?"

"I don't think we can. It has to be the user to control it." Obito answered. "Only Naruto can revert it back now."

The 6-year-old blonde clutched at his head as pain wracked it. The headache was still as painful as it was when he opened Obito's Mangekyou.

"What can we do?" Tobi helplessly asked.

"Keep training him. Obito should be able to help Naruto learn how to use his Mangekyou. Maybe even teach him how to revert it down to Sharingan to ease the pain."

"I'll try to help him deactivate it first. We can't just jump to Mangekyou right away." Obito agreed.

"Karin, heal him."

The girl immediately moved over and placed her hands over Naruto's head to supply healing chakra. The soothing Uzumaki energy mixed into Naruto's chakra network and slowly brushed the pain away.

"What if we make him practice everyday?" White Zetsu suggested.

"That will double the load for Karin."

Whenever Obito was around, Karin was forced to supply Uzumaki energy into his eyes while the Uchiha cycled his own energy. Black Zetsu believed that pushing the bounds would accelerate the manifestation of the Rinnegan inside Naruto's eyes.

Then again…maybe doing the same for Naruto would accelerate the Rinnegan-ification of Obito's Mangekyou too.

"On second thought- Naruto, make sure to practice with Obito's eye whenever you can. Have Karin heal you if it becomes too much."

"Do I have to…?" Naruto grumbled from his position on Karin's lap as she healed his eye.

"Do you want your vision back or not?"

"..."

The answer to that was obvious.

"...of course."

"Then train. Until you can use Obito's eye without problems."

He'd have to.

It was his only choice.

Author's Note

Blitzed this chapter out between all my other fics. Whew, I'm really pushing myself to keep my word goal for this month.

I made Naruto blind because I wanted him to learn how to live and fight without vision later. At the same time, he develops into a sort-of-Kakashi with an implanted Sharingan. All the while, Black Zetsu is maturing three brand-new Rinnegans from his and Obito's eyes.