Massacre.
Tendo ignored him and started to absorb Haku's chakra. He knew Naruto was a very naive character at this point so he didn't care for his outbursts. Naruto saw Haku's body losing color and he couldn't control himself anymore. He sprinted towards Tendo and tried to punch him off of Haku.
Naruto: "Get off of him!"
Tendo: "You asked for it."
Tendo had his back turned to Naruto so Naruto thought that he could land a clean hit on him before he turned around. Tendo ducked under the punch as he was still absorbing chakra from Haku and used yhe Hidden Snake Hands Jutsu with his free hand, binding Naruto with a white snake. Kakashi appeared in between the two put his hands on both of their shoulders.
Kakashi: "Leaf shinobi should not be fighting amongst each other. Naruto, you're being very confrontational against one of your comrades. W-"
Naruto: "HE IS NOT MY COMRADE! HE IS AN ENEMY! HOW COULD HE KILL SOMEONE LIKE THIS?!"
Kakashi: "Sigh...Naruto. He had killed the two brothers from before just like this. What makes it different now?"
Naruto: "Haku wasn't a bad person! He was only a tool for Zabuza! We could've helped him and he killed him! Is this what it means to be a shinobi?! He's even taking his chakra like he felt nothing after killing someone! A-a shinobi like this is no comrade of mine! When I become Hokage, I'll change the hearts of evil people like you and show you the error of your ways!"
Kakashi: 'Naruto...'
Tendo: "You're a fool who thinks because you deem someone a good person they deserve to live more than another. I kill whoever I need to impartially, regardless of their good or bad. Your way of thinking is just stupid. Plain as that."
Kakashi: "Naruto. Tendo. Stop arguing. We have company."
Tendo already noticed who Kakashi was talking about as he had seen them coming in that direction a while ago. He ignored them, released the snake around Naruto, and walked towards Zabuza's body after he finished absorbing Haku's chakra and taking his weapons. He had also gotten a few new Jutsu from Haku, namely the Demonic Ice Mirrors and the Flying Water Needles Jutsu.
Gatou: "So, 'The Demon of the Mist' is finally dead huh? Some demon he is if he can't kill an old man and some random ninja."
As Gatou went on talking, Tendo was just finishing up absorbing Zabuza's chakra. Sakura and Tazuna were just watching on as he did this. Sasuke had already woken up a bit so sakura had already started to calm down when Tendo arrived and freaked her out once again.
Sakura: "Why do you keep doing that? Is that really necessary?"
Tendo: "I do it because I want to. Simple as that."
Sakura: "...."
She didn't have anything to say to his response. She couldn't stop as she was too weak right now and there was nothing saying Shinobi couldn't do this. Tendo got up and scanned his memories as he searched for the new jutsus he just acquired.
Tendo: 'The Water Dragon Bullet Jutsu and the Giant Vortex Jutsu. These two Jutsu will be extremely useful in filling the terrain with water in later land battles. Their destructive power is also nothing to scoff at. Now, to get to what I really let these two go in the first place for.'
Tendo flickered and appeared standing right in front of Gatou. He was about to kick Haku's body when Tendo arrived. Gatou was surprised by how fast he appeared and immediately started ordering his men to attack.
Gatou: "Kid, runts like you who think they're geniuses just because their shinobi are destined to die by my hands. We just waited until all of you were worn out hehe. Now you're defenseless. Die! Men, Attack!!"
The men all laughed and screamed in vulgar fashions as they rushed towards the team. Tendo jumped back and quickly formed multiple hand signs.
Tendo: "Water Style: Giant Vortex Jutsu!"
A large amount of water flew up from both sides of the bridge and formed a ring around Tendo's body before shooting out at the men that were coming. As the men were drowning in the massive wave of water, Tendo knelt down and put one of his hands on the water while making a hand sign with the other.
Tendo: "Water Style: Water Whip Jutsu"
The water started to manifest multiple whips from all directions and Tendo directed them into all the orifices of the men. The water went into their ears, making some of their heads explode from the pressure while for others it went into their lungs and exploded their chests outwards, leaving their rib cages and the rest of their internal organs exposed. As more of them were killed, their blood got mixed up into the water and before long, it looked like he was controlling the blood itself.
Sakura was vomiting uncontrollably as she saw this sight. Tazuna had to reconcile her but even he wasn't faring much better. Naruto was speechless as he heard the cries of all the men inside. He had never seen such bloodshed and slaughter before. All of this was new to him.
Kakashi: 'What could've happened to this boy for him to become so ruthless? He was an orphan but, that's it. From what I heard, he lived a pretty normal life. Is he just sick in the head?'
At the end of it all, as everything died down, Tendo could be seen standing in the middle of the massacre with the body of now fully discolored old man in his hands.
Tendo: 'So this is where he hides his money huh? Multiple sealing scrolls in a hidden vault in his house on an island not too far from here. Tonight, I'll go take it from him before we go back to the leaf village tomorrow. It should provide enough funds for me to survive for about a decade or so. He was one of the richest men in this area. After all, im sure he won't mind if I do.'
Tendo threw Gato's body to the side and started walking back towards the rest of the team with bloodstains scattered all across his face and hair.
Tendo: "Mission Complete."
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Tendo's current system status:
Name: Tendo Hyuga
Age: 12 years old
Chakra Affiliations : Water, Wind, Ice
Dojutsu: Byakugan
Shop Points: 580 [MC had 80 before he killed all those men and he just killed 50 of them. All of them giving him 10 points each so now he's at 580.]