Hiraishin no Jutsu
That evening, after dinner, Zabuza took Haku to the dungeons. "Zabuza oji-san, what do you want to talk about? Why do we have to go to the dungeon?" asked Haku.
"I thought you were ready to practice a new ninjutsu. I can't learn it, so I'll give you the scroll. Learn it, I'm sure you can." Zabuza said while handing him a scroll.
Haku accepted it and read it. He was surprised to learn that this scroll was a scroll that contained a space-time ninjutsu, hiraishin no jutsu. "Zabuza-ojisan, this… How did you get this scroll?" asked Haku who was surprised but inside he was very excited when he found out that he would learn the fourth Hokage's mainstay, Minato Namikaze.
"You can assume that a friend of mine gave me this scroll. He said you had a talent for learning that move, that's why he gave me the scroll. But I have to give it to you when your chakra is at the level of elite jounin. Study it and improve your skills." Zabuza said.
In an instant, Haku jumped up and hugged Zabuza, with a big smile, Haku looked at Zabuza, "Thank you very much, Zabuza-ojisan. I will definitely master this move!!" said Haku cheerfully. Zabuza was also happy to see a cheerful Haku. Then he left Haku to give him time to start learning the move.
A few days before the training camp, Haku spent learning Hiraishin no Jutsu. Day and night, he only rests 2 hours a day and only at mealtimes. Zabuza let it be because he knew Haku was used to not sleeping for days when he was still a shinobi in Kirigakure village.
And finally, with Haku's intelligence, he was able to understand all the important points to learn that space-time move and began to practice it by making hiraishin seals on his hands and making them for his sword weapons.
Haku has a sword weapon that he brought with him when he left the village, but he never used it again. Now, Haku will start wearing it again. Haku also asked Zabuza to order a special weapon for that space-time move.
But unfortunately it can't be before Haku goes to the training camp. Because of that, he made temporary seals on some of his iron needles.
"Alright, now it looks like I've made enough of this. Really drains chakra. I'll try it at training camp tomorrow." Said Haku who was drenched in sweat. He was so excited that he devoted all his focus to his new move.
"Ah… By the way, I want to try that Jutsu. I wonder if without the contract, what kind of creature would come out." Haku muttered then went upstairs and took a shower.