In the fight with Haku. Naruto sacrificed himself for Sasuke.
"Why would you save me dobe." Sasuke
"Even though I don't like you. We are teammates. We have to look out for each other." Naruto
"So this is how I die. I hope the next life will not be as hard as this one." Naruto thought before he closed his eyes
"Naruto" Sasuke
Seeing that Sasuke was distracted Haku took the opportunity to put Sasuke also in a near death state.
"I should go help Zabuza-Sama now." Haku thought
With Naruto
"Tōshirō. Wake up Tōshirō" A voice said"Who is Tōshirō. "Naruto thought before he woke up
Naruto woke to see he was in a giant barren landscape of ice with no discernible features but a moon. With him there was a Ice Dragon.
"Who are you" Naruto
"Remember Tōshirō. Remember" The dragon
"Why is it calling me Toshirō. Tōshirō. That name I feel like I know that name. " Naruto thought
Suddenly he's mind was filled memories of a previous life. Naruto clutched his head as he felt intense pain from recalling the memories.
"Hyōrinmaru" Naruto
"Nice to see you again Toshirō-Sama." Hyōrinmaru
"You too." Naruto smiled
In the real world
Haku was about to cancel her mirror technique. Suddenly a blue aura exploded from Naruto's body. A large amount of spirit pressure was being released."When people are protecting someone truly precious to them. They truly can become as strong as they need to be. Is that really the case. "Haku thought as she felt the intense pressure
"What is this intense pressure and that blue aura" Zabuza thought
Zabuza was in a bit of stalemate with Kakashi who was blocking his sword with kunais.
"I have to hurry and beat him. So I can help those two." Kakashi thought
Tazuna and Sakura weren't faring so well. They felt like passing out from the pressure.
Few seconds later the aura faded and the pressure disappeared.
Haku saw Naruto's new appearance.