Goddess of Ice; Reborn as Naruto's twin sister

*Author Note*

I added a few paragraphs to the start of the last chapter.

*Author Note end*

"[Wind Style: Raging Wind Armor]"

The chakra cloak surrounding Naruto changed viscosity. Now, instead of simply engulfing him with chakra, the chakra was flowing all around his body, grinding everything it touches apart. It took Naruto a long time to reach the necessary proficiency with this jutsu to not hurt himself with it.

"[Water Style: Perfect Water Domain]"

Hinata's chakra dispersed into the air, seemingly not doing anything. Even those proficient in sensing chakra would have trouble noticing the difference. Hinata can now freely control and create water around her in a radius of 2 meters. Although the effective range is much shorter than the version, she used against Kurenai, now she can freely move around while using it and her control over it is much more precise as well.

"[Ice Style: Domain Creation: Heavenly Realm of Eternal Ice]"

The temperature in the arena started to decrease immediately. At first, the ground under Yuna's feet froze and was covered with ice. Then, more and more ground was frozen over, until not only the ground but even the walls of the arena were covered in ice. The only two places not frozen were around Naruto and Hinata. In Naruto's case, the ice was simply shredded away by his armor, while in Hinata's case it simply couldn't push into her domain.

Simultaneously, most of Yuna's body was covered in a thin layer of ice as well, giving her red chakra-cloak an ice armor. The only place, not frozen over, was her head, with the exception of an ice diadem with 9 upwards-pointing spikes on it.

As soon as Hiruzen saw Yuna using ice, he stood up and looked at Yuna with pure astonishment. There were always a lot of ridiculous things surrounding Yuna, but in Hiruzen's opinion, this tops them all.

'How can this be even remotely possible? It is impossible to use ice style without the corresponding Kekkei Genkai. Does she have a mutated bloodline? But how?'

Orochimaru reacted similarly, but his thoughts were a little different.

'To think Konoha was hiding someone with the ice style. No wait, sensei seemed to be surprised as well. Is Danzo involved in this? But why does she have the Kyuubi in her? This will make it much more dangerous for her to have a lot of children. Something is fishy here. I think I should spend some time investigating the matter after the invasion is over.'

The most surprised person, however, was definitely Kakashi.

'My Sharingan copied that jutsu...How? The Sharingan cannot copy a Kekkei Genkai. Does that mean that it wasn't one? I would like to test that, but just thinking about using that jutsu overheats my brain and almost melts it. How in the world can she handle that?'

A wide grin appeared on Yuna's face when she saw Naruto's and Hinata's new jutsu. In the last month, these two insisted on training without Yuna being present. She could have probably followed them stealthily but decided against it. Where would be the fun in that, after all?

"It seems like you two worked hard. Come! Show me what you can do!"

""YES!!!""

Naruto vanished from where he stood and punched towards Yuna. Yuna caught the blow and the sound of sharp winds scraping against ice echoed through the arena. Simultaneously, ten drops of water were generated around Hinata and shot at Yuna with insane speed. They were, however, blocked by an ice wall that simply rose out of the ground.

An ice spike appeared behind Naruto and shot towards his back, while Yuna threw another punch from the front. Naruto ignored the ice spike and blocked Yuna's punch while the spike was blocked by Hinata, who appeared next to Naruto. This time, instead of multiple small water pools, one big blob of water appeared and shot towards Yuna.

Yuna swiftly ducked underneath it, causing the attack to fly over her head and tear a deep gash into the arena wall. Yuna jumped back to get some distance from the duo and at the same time, massive amounts of ice spears were created all over the arena and shot towards Hinata and Naruto. While Naruto simply punched them into ice dust, Hinata used small amounts of water to change their trajectory, causing them to miss her and Naruto while smashing against each other. The combination of her Byakugan and her small domain allowed her to do so almost effortlessly.

Just when they finished blocking all the projectiles, a massive wall of ice came crushing towards them. They made eye contact with each other for a moment, nodded at each other, and started to gather massive amounts of chakra.

"[Water Style: High-Pressure Water Blade]"

"[Wind Style: Ferocious Wind Blade]"

The two jutsu combined mid-flight and created a powerful stream of water and wind, that sliced through the ice wall, splitting it in half. The two parts of it crashed down on the ground, missing Naruto and Hinata.

"Haha, not bad. Not bad at all. You two have powered up quite a bit in the last month."

Naruto could only smile wryly at that compliments.

"Yeah, nee-san, and you are as monstrous as always."

Although Hinata didn't say anything, she still nodded her head.

"Hehe, naturally. I am the big sister after all. Let's keep going, there is still a lot of fun to have."

Two thin swords made out of ice were created in Yuna's hands. A wide grin appeared on her face as she restarted the fight against Naruto and Hinata.

The audience, meanwhile, was mostly silent, while they looked at the fight unfolding in front of them with awe. Wind and water were constantly slicing through ice, while fist met fist and sword met sword. The ice on the arena wall and ground was torn to shreds just to reappear a few seconds later. The temperature in the whole stadium was getting lower and lower, while Yuna's ice kept creeping upwards. Those sitting closer to the arena already started to shiver as everything in the stadium was slowly but surely being frozen over.

Hiruzen had no idea what to make of this. It didn't look like Yuna was putting chakra into it, but despite that, the ice was encroaching more and more of the stadium. He quickly stood up to give a few commands.

"All shinobi capable of using fire jutsu are allowed to freely use the [Fire Style: Fireball Jutsu] to push back the ice from the spectator stands. You are NOT allowed to intervene in the fight in any way."

Orochimaru, meanwhile, was almost drooling while watching the fight.

'What is this? Why does the ice react like this? I have studied the Yuki clan and their Kekkei Genkai didn't work like that at all. Is it a new Kekkei Genkai? I absolutely need a sample of her blood. I need to study it no matter what.'

The person most affected by the ice, however, was Genma Shiranui, who was inside the arena as well. He was frantically circulating his chakra to keep the cold out of his body and had to frequently dodge all kinds of stray projectiles that were flung around the arena.

A few more minutes of exchanging attacks back and forth passed, and the fight was paused for a short while yet again. Yuna still seemed to be fine. There were a few places on her clothes that had her blood on them, but the wounds that were the reason for that were already healed due to Kurama's chakra. Although the creation of her jutsu costs massive amounts of chakra, maintaining it is actually rather cost-efficient, so she was still doing fine in the chakra department.

Naruto had, due to the same reason, no wound on his body either, but his wind amour was eating massive amounts of chakra, so he was already pretty spent. Hinata, on the other hand, had a few scratches on her, but no serious wounds either. This was simply because Naruto was much more efficient in close combat, so Hinata took the mid-range roll. Although the amount of chakra her jutsu used was much easier on her reserves than Naruto's, she didn't have that much chakra from the start, so she was also running pretty low.

"Haha, seems like things are coming to an end. How about we finish this with a bang?"

The two swords Yuna was holding disappeared and instead, one big sword appeared in her hands. She grabbed with both of her hands and slowly lifted it up so she could slash it downwards.

Naruto and Hinata nodded their heads as both of them stopped using their jutsu. Since Yuna wanted to finish this with a bang, they would naturally use all they have left. Naruto approached Hinata and stood next to her. He lifted up his hand and a blue sphere of chakra started forming and started growing bigger and bigger. As soon as the sphere appeared, Hinata put her hand near it and started to inject it with water nature chakra and stabilized it with natural energy. Naruto and Hinata have been fighting together and against each other for a long time now, and synchronizing their chakra with each other has pretty much become child's play for them.

After a few more seconds, Naruto held a massive sphere of blue spinning water chakra in his hand, while Hinata staggered backward due to her chakra hitting rock bottom.

"Hope you are ready, nee-san. Here it comes!"

Naruto lifted up the giant chakra sphere and threw it at Yuna.

"[Water Style: Torrential Rasengan]"

An insane smile appeared on Yuna's face when she saw the massive chakra sphere flying her way.

"HAHAHA, GOOD!!! VERY GOOD!!! A WORTHY FINAL MOVE!!!"

"[Ice Sword Combination Style: Heaven and Earth Splitting Frozen Slash]"

Yuna slashed down with her sword, causing a very thin line of ice to shoot out of it. It seemed to be incredibly fragile, yet the moment it came into contact with the giant chakra sphere, the sphere got sliced in half without any resistance. The ice kept moving unhindered and passed through Naruto and Hinata without touching them. When it reached the arena wall, it sliced through it without stopping and finally flew out from the other side of the wall and vanished into the sky.

The Rasengan, meanwhile, exploded after being cut in half, causing it to shoot massive amounts of deadly water torrents all over the arena. Naruto's eyes widened before he used the last drops of chakra he had to protect Hinata and himself with a few earth walls, while Yuna simply defended herself by creating a few ice walls in front of her.

Kakashi, meanwhile, covered his Sharingan with his hand while groaning in pain. The moment Yuna swung her sword down, he felt like someone had pierced a needle into his eye. There was actually some blood coming out of the corner of his eye as well. He had no idea what exactly happened, but whatever Yuna did, completely overloaded his Sharingan to a frankly perverse degree. Considering that incredibly fragile-looking string of ice cut pretty much everything in its path unhindered, Kakashi wasn't even surprised about that. He had no idea what Yuna did but was certain that it was not something that could be blocked or even understood.

Yuna, meanwhile, almost staggered when she finished her attack, but managed to look unbothered. She got a bit carried away and actually used sword Ki in her last attack. Sword Ki was something only people at a rather high level could use. A level, Yuna was still very far away from. She, naturally, knew how to use it in her past life, but that doesn't mean she could use it in her current life. Well, she could, but it puts quite the burden on her.

'I got a little too excited there, but can I really be blamed for that? The jutsu they used was quite powerful, after all. If that hit me, even I wouldn't survive it.'

[Seems like those two took Minato's jutsu and improved it, huh? While Naruto donated the chakra, Hinata was responsible for the natural transformation and stability. Even I have to admit, that it was quite monstrous.]

'Haha, indeed.'

After the dust settled, a slowly crumbling earth dome was revealed. Inside of it, both Naruto and Hinata were lying spread on the ground while breathing heavily.

Yuna approached them with steady steps and stopped just a few meters away from them.

"That was an impressive move. Well done."

Although the compliment caused Naruto and Hinata to smile, this was all they could do for now. Yuna looked around in the arena, to look for the proctor, and moments later she moved to a small pile of rubble and pulled him out of it.

"Yo, mister proctor, time to declare me as the winner."

Genma shook his head slightly to get his thoughts back on track. When the Rasengan exploded, he barely managed to raise an earth wall to protect himself. Unfortunately, that one wall wasn't enough to endure the whole onslaught, so it crumbled and buried him underneath it.

He scanned the arena and the first thing he noticed was that the ice was actually thawing and that the temperature was slowly increasing. Next, he noticed that Naruto and Hinata were both lying on the ground without moving. He could see that they were breathing so he wasn't too worried about them.

He shakily stood up, and after giving the current situation another glance, he lifted his hand and made the announcement just to...

"Winner of this fight: Yuna Uzumaki! *Thump*"

...faint immediately afterward and fall back to the ground.

Yuna happily walked over to Naruto to give him a hand so he could stand up.

"Well done, Naruto, very impressive."

Although Naruto blushed a little, he still accepted the compliment with a happy smile. Next, instead of giving Hinata a hand to stand up, Yuna simply picked her up in a princess-carry, causing Hinata to utter a weird scream.

"Hehe, well done Hinata. You have really grown strong."

Hinata blushed a little and was about to answer when Yuna lowered her head and gave her a deep kiss. At first, Hinata still struggled a little, but after a short while, she leaned into the kiss and even started to hug Yuna.

After a short moment, the two separated, and as soon as Hinata remembered that they were currently in front of a massive crowd of people, she fainted out of embarrassment.

'Hehe, shy Hinata is still the cutest.'

[Ding! You have gained experience for skill: Shamelessness.]

[Ding! You have already reached the maximum level of skill: Shamelessness. No further advancements are possible.]

'...'

*Author note*

Well, there won't be a second chapter today, simply because this one has the length of two chapters. I could split it in half, but see no reason why I would do that.