Zabuza Momochi, Demon of the Hidden Mist

Such powerful killing intent. It's almost as strong as Kakashi-sensei's. It's terrifying. I've never seen him act like this before. Have you changed, Issui-kun? Sakura thought as she watched Issui standing on the water.

"You... this is our mission. Please don't interfere. If there's anything..." Kakashi said to Issui, trying his best to stop him.

"Kakashi-senpai, if I remember correctly, the mission you accepted was supposed to be C-rank. It didn't seem to include fighting a missing-nin, so please let me do this. I came here today prepared to die. Either he dies or I do. He's strong, but I'm not weak either. And no matter what happens to me, please don't intervene. This is a battle for a ninja's honor!!!" Issui said calmly. The chakra in his body had already taken physical form, gathering on the surface of his body.

"I... see... all right, then. Be careful," Kakashi said. He left the water and appeared beside Sakura and the others.

"Kid, I don't know you. Is there some great grudge between us?" Zabuza asked.

"Six years ago, one morning in Heaven Village, you led a group into the village and killed everyone, including my grandfather. I was the only one who survived. Come on, Zabuza. I've carried this hatred for six years, living in the shadows every day, unable to show my true feelings. All I could do was work harder and harder, surpass myself, and train as though tempered by fire. Now I've gained great strength. There's still a gap between us, but it's only a small one. Come on, don't hold back, or you'll be facing the god of death!!! Genjutsu-Death God Encounter Technique!!!" Issui said calmly, but his killing intent had already taken physical form, and specks of gray energy were rapidly forming.

This gray energy was the hatred of Issui and his enemies, accumulated over years of battle. All of it surged forth at this moment. This was a genjutsu in which one could lose oneself with the slightest lapse, wandering among thoughts of cursing oneself and others. Once one could no longer endure it, one would commit suicide!!!

Genjutsu was the weakest of all Zabuza's abilities, and in an instant, he was trapped in his own mental world. He saw himself killing all his classmates during his ninja graduation exam as a child. Then they turned into ghosts and circled him endlessly, viciously tearing at his soul and cursing him to hell...

"Sensei, why did Zabuza stop moving? And why does he look so terrified...?" Naruto asked.

"It's a genjutsu, and an advanced one at that. I never expected him to create his own advanced genjutsu. What a genius..." Kakashi said, looking at Issui on the water. "Genjutsu?" Naruto asked.

"You idiot. Genjutsu is a mental attack and one of the three essential ninja skills-ninjutsu, taijutsu, and genjutsu. Genjutsu disrupts the normal flow of an opponent's chakra and traps them in a world of illusions to achieve its purpose. An advanced genjutsu can even cause a person's mind to collapse in an instant, leaving them caught between life and death," Sakura explained.

"That's the girl I like for you!" Naruto praised her.

"This idiot, that's common knowledge." Sasuke was speechless at Naruto.

Five minutes later...

Zabuza suddenly opened his eyes on the water, but his forehead was covered in sweat, his face was pale, and his limbs were weak. His mind had presumably suffered a severe blow.

"Well, you really are Zabuza Momochi, the man they call the Demon of the Hidden Mist. You actually managed to break out of a mental genjutsu like that. Not bad. Things aren't looking good for you now, though. I'd love to kill you, but after carrying out so many assassination missions, I'm not an idiot who acts on impulse. You've lost what little confidence you had, haven't you? You must be wondering just how strong I've become. Your mind has suffered a severe blow, and your fighting strength has fallen by more than half. You're figuring out how long it'll take to kill me and make a clean escape, aren't you?" Issui saw through Zabuza's thoughts at once.

"You..." Cold sweat gathered on Zabuza's forehead again. This kid really is something. How does he know what I'm thinking?

"Oh, now you're thinking, 'This kid really is something. How does he know what I'm thinking?' aren't you? Your world is under my control now, Zabuza. Give up. Rather than struggle so painfully between life and death, you might as well die..." Issui sneered. After Zabuza had awakened from his genjutsu, Issui had placed him under another, the simplest genjutsu of all—the Hell Viewing Technique.

There were two reasons Zabuza hadn't noticed: first, his mind had already suffered a severe blow, and second, Issui's words had distracted him. This was a battle in the mental world.

"How do you know what I'm thinking, kid?!!" Zabuza and Issui said the same words at the same time.

"That's not right. I've already escaped your genjutsu. There's no way you can know what I'm thinking." The two spoke at the same time again.

Naruto, Sakura, Sasuke, and Tazuna were all stunned on the shore. They were saying exactly the same things. It was too eerie.

"Two layers of genjutsu? This child really is a genius. Judging by genjutsu alone, he's not much worse than Kurenai..." Kakashi's expression changed as well. Manipulating the enemy's mind? What a perfect tactic.

"All right, kid, let me show you what I can do..." the two said at the same time again.

"Ox, monkey, rabbit, rat, boar, rooster, ox, horse, rooster, rat, tiger, dog, tiger, snake, ox, ram, snake, boar, ram, rat, water, monkey, rooster, dragon, rooster, ox, horse, ram, tiger, snake, rat, monkey, rabbit, boar, dragon, ram, rat, ox, monkey, rooster, water, rat, boar, rooster. Water Release-Water Dragon Bullet Technique!!!" The two formed hand seals simultaneously.

In fact, Issui hadn't copied Zabuza's ninjutsu. At this point, a careful observer would have noticed that Issui was 0.3 seconds behind Zabuza. The reason he could use the same ninjutsu was that he knew the few Water Release ninjutsu Zabuza often used very well. By analyzing the first and second hand seals of those ninjutsu, he could quickly tell which Water Release technique Zabuza was about to use. Then he sped up his own hand seals slightly to catch up with Zabuza. Finally, with the addition of genjutsu, he directly reproduced Zabuza's every movement and expression, creating this effect.

Two identical water dragons rose from the water and finally vanished together, leaving everyone present marveling in amazement.

"Damn it, how did you know I was going to use the Water Dragon Bullet Technique?!!!" the two said at the same time again.

"That's amazing! How did he do that?" Naruto asked Kakashi.

Sasuke also looked at Kakashi. Though the battle wasn't particularly grand in scale, it was truly spectacular.

Sakura was excited too. She had thought Issui would impulsively rush forward to fight, and hadn't expected anything like this to happen.

"Watch carefully. You need to pay attention. You're the same age, but the gap between you and him is simply enormous. Especially you, Naruto. You have too little combat experience and you're impulsive. Though you've improved, it's only been a little. And Sasuke, among your peers, there are many who are better than you. If you want to surpass them, you'll have to work even harder. I don't know how you usually train, but you're far behind Issui in that regard. And Sakura, your fundamentals are actually good, but you seem to be the worst fighter of the three." Kakashi dealt the three of them a blow in turn. In fact, he had already seen through Issui's little tricks with his Sharingan, but he was still amazed by him. Issui's grasp of his opponent's psychology had reached the utmost limit, and this was clearly the result of extraordinary combat experience and awareness.

"Impossible..." the two said at the same time again.

"Tiger, ox, monkey, rabbit, rat, boar, rooster, ox, horse, dog, tiger, dog, tiger, snake, ox, monkey, rabbit. Water Release-Great Waterfall Technique!!!" The two formed hand seals at the same time once more. The entire lake surged violently, and even large swathes of trees on shore were swept away. Kakashi and the others had moved out of the way long ago. The powerful torrent continued to rage for a long time before finally stopping. Once the lake had calmed, they looked back at the area where the two had been fighting.

Only Zabuza remained in the battle area. Issui was nowhere to be seen, and had most likely been swept away by the water.

"Hmph, a kid is just a kid. Whe-" Zabuza had just begun to mock Issui when a sound behind him caught his attention.

"Lightning Release-Thunder Totem Battle Axe!!!" Issui used his newly created Lightning Release Ninjutsu, giving lightning nature physical form as a gigantic thunder battle axe to strike down his enemy.

"Hummm..."

The enormous lightning battle axe struck Zabuza. The violent impact made blood pour from his seven orifices and sent him straight into the water. The axe's strike continued downward, and the water conducted the electricity, covering the surface around Zabuza with ceaselessly darting serpents of lightning.

After all the lightning vanished, the unconscious Zabuza floated to the surface, having been knocked out by the Lightning Release attack. Just as Issui approached with a shuriken to kill Zabuza, two senbon suddenly appeared and pierced Zabuza's neck.

Just as in the original story, Yuki Haku appeared beside Zabuza. She had arrived just in time.

"He's already dead..." Kakashi appeared beside Zabuza as well.

"Thank you for your help. I've been looking for... a chance to kill Zabuza for certain," Haku said calmly to Issui, as though the person she had just "killed" hadn't been human.

"You're with the Hunter-nin Corps of Kirigakure Ninja Village, aren't you...?" Kakashi said.

"You know quite a lot," Haku said.

"Hunter-nin Corps?" Naruto asked.

"You don't even know about the Hunter-nin Corps? They taught us that at the academy. The Hunter-nin Corps are... ninja assassins who specialize in hunting down ninja who've fled their villages for one reason or another, like Zabuza. They do it to keep the village's secrets from leaking out. That's common knowledge. You should really study harder!" Sakura explained to Naruto.

"That's right. My mission is to hunt down ninja who have fled. I'm a member of the Kirigakure Hunter-nin Corps," Haku confirmed.

Judging by her height and voice, he should be about the same age as Naruto and the others. The Hunter-nin Corps... he's no ordinary kid, Kakashi thought.

"Who are you, anyway? I'm asking you...!" Naruto couldn't stand it anymore. He ran to the edge of the lake and shouted angrily at Haku.

"Don't worry, Naruto. He isn't an enemy," Kakashi said.

"That's not what I'm asking! Zabuza... he killed Zabuza! Someone that powerful was killed so easily by a kid about my age! Doesn't that make us look like fools? How am I supposed to accept that? Even Issui had to put in a huge effort just to knock him out!" Naruto cried out in frustration.

"I understand how hard this is for you to believe! But it's a fact. There are kids in this world who are younger than you and even stronger than me..." Kakashi said, looking at Haku and Issui before turning to Sasuke.

"Hmph!" Sasuke was a little angry. Why are you looking at me? I know I'm not all that strong yet...

Haku hoisted Zabuza onto her shoulder, preparing to carry him away.