Brought to Konoha to become the Kyubi’s Jinchuriki, Kushina was very afraid of inheriting this power.
That lasted until she heard her predecessor, Uzumaki Mito, say to her: “We came here to be the vessels of the Kyubi … But before that, we must find love and fill the vessel with it. Then, even if we had to live as the Kyubi’s Jinchuriki, we could still be happy.”
And with Minato’s support, Kushina was able to put down her fears of the Kyubi and to overcome it.
Then, Ryo came along, and his words: “Biju can coexist with humans in peace!” changed her attitude towards Kurama drastically.
His sentence gave her courage to try and reach out to the Kyubi.
With time, she got to know it, only to realize that this so called demon was no more than a big angry fox.
With that, she had no more fears of Kurama, and often talked to him about what happened in her life.
For Kurama, Kushina also was special. Besides the Rikudo Sennin, she was the first human he ever felt good about.
At the beginning, he could feel all her fears and worries. With time, he felt her attitude changing slowly. After Hearing ryo’s words, she started observing him from time to time.
Being sealed into her body, the Kyubi could do nothing about that. He could only pretend to be asleep all the time.
What he didn’t expect was that after a while, she was no longer satisfied with just observing him. she began talking to him directly about the boring things in her life. Along with that, the Kyubi also started sensing her goodwill towards him.
Feeling Kushina’s goodwill, was no longer that stubborn, and occasionally started answering her with a few words.
Getting along like that made the Kyubi a lot less wary against Kushina, until she asked him, one day, if he wanted to see the world outside.
With that, they reached a consensus: Kurama doesn’t try to take over Kushina’s body, and she removes her seals that she put upon him.
As soon as she did that, the powerful hatred within the Kyubi took over, causing her to go rampant. However, when she came out of it, not only did she not blame him for that, but she also said she believed in him. With that, the last brick in the wall between them was taken away.
For the first time, Kurama felt this good to have a Jinchuriki.
He started helping Kushina control his power, and Kushina started being able to use his powers reliably.
Originally, Kurama thought that he could stay with Kushina until she grows old, but Ryo’s behavior made his suspicious, and his answer made him knew that things weren’t going to be that easy.
Then, recently, there was the Roran incident, and he saw the young teenager that actually had his powers.
With that, Kurama knew for sure: One day, he will be extracted and even manipulated to kill Kushina.
Since that day, Kurama had been forcing Kushina to practice, and pushing her towards the mastery of his powers. He knew, that whenever she’s able to become a perfect Jinchuriki, he should be afraid of no Genjutsu.
Under his special training, Kushina became able to control the Seven Tailed Cloak mode. He was very satisfied with her progress.
Therefore, when she wanted, just like the Nibi and Hachibi Jinchurikis, to turn into a full Biju form, Kurama ended up agreeing in the end after some reluctance, as a reward to her efforts in training.
On the battlefield, the 3rd Raikage ordered the Ninjas to retreat and leave the battlefield to his two Junchuriki.
Han and Onoki’s faces were heavy as they came out of their troops. Han knew that he couldn’t cope with either of the two, as he wasn’t a perfect Jinchuriki. And even with Onoki’s help, they shouldn’t be able to win.
Minato knew that all too well, and prepared to join the two for the fight.
“Minato, wait! This is my fight!” Kushina stopped Minato.
The latter never saw such a serious look upon his face.
Seeing Kushina’s firm eyes, he knew that he could never stop her.
He smiled, and left the matter to her. She put his Kunai into her bag, and entered the battlefield.
Onoki and Han looked strangely at Kushina. Her strength appeared to be Kage tier to them. But the amounts of Chakra owned by the enemies were immense, and such a battle should be one that could bring death upon her.
She paid no attention to the eyes of the two, for she felt the pressure of the two Biju’s Chakra as she approached them. However, she didn’t have the slightest fear.
“Kurama, let’s show them who the best partners are!” Finishing her words, she was wrapped in the Kyubi’s Chakra, her body became golden, and behind her appeared a golden Cloak.
The people in the center of the battlefield were stunned by her Changes, and everyone could feel the immensity of the vast ocean of Chakra within her body.
The two enemy Jinchuriki’s looked at each other, and they Joined forced to use Biju dama. They already knew that it was the Kyubi, the most powerful existence in the universe.
“Crush them!” Facing the bombardment of Biju dama, Kushina subconsciously wanted to dodge. But she heard the Kyubi’s words, and her confidence increased enough to take Ryo’s Ice Blade, infuse it with the Kyubi’s Chakra and use it to destroy the two Biju Dama
Minato sighed and noticed that his back was soaked in sweat. Kushina facing the two Biju Dama scared him to death.
“The Kyubi! It’s the Kyubi!” After that face off, the Gobi within Han’s body trembled.
For the first time, Han heard the Gobi panicking in such a manner. While Kyubi’s performance just now was so magnificent, it shouldn’t be that scary to the Gobi.
Then, Han knew why the Gobi was so afraid. Right after Kushina destroyed the two Biju Dama, the Kyubi’s transformation started reaching completion.
Not so far from the battlefield, Ryo was leading the rest of Konoha’s Ninjas to battle. From time to time, he sensed the battlefield with his Sage Mode.
Suddenly, he felt a powerful familiar Chakra, and felt smothered by it’s pressure.
“The Kyubi had appeared!”
On the battlefield, a golden Kyubi appeared in the middle, turning everyone quiet. Even birds and vultures in the sky stopped making any sound.
That horrible Chakra, made everyone terrified, and Han understood well why the Gobi was so afraid.
For the Cloud, the Nibi stepped back a few steps after seeing the complete Kyubi.
In the Manga, the Kyubi was able to defeat five Biju on his own, earning the Hachibi’s praising. Now, with its full appearance on the enemy side, the Hachibi felt terrified.
“When did Kushina completely control the Kyubi?” Minato was surprised to see the Kyubi.
“Kushina, only two minutes. I’m too strong, and your body and mind will not stand my Chakra. More than two minutes, and my hatered will take over.” The Kyubi reminded.
“Let’s go, Kurama!” said Kushuna, with her eyes on the two Biju in front of her.