Zabuza and Kakashi managed to stay on their feet while Kiba and Sasuke keeled to their knees, unable to withstand the sudden weight of Naruko's uncontrollable rage slamming into them. Being experienced shinobi, the two men were still able to stay standing but were finding some difficultly in moving.
"N-Naruko!" Sasuke gritted his teeth, knowing that his friend had lost control of herself, thus the release of the Kyuubi's chakra.
He hadn't experienced the Kyuubi's chakra before, only knowing what it felt like when he had been told by those who had experienced it first hand. And when he said that it was anything alike what they had mentioned, he'd be wrong.
It was so much worse.
Like the weight of the world on his shoulders, he struggled to even move an inch. But his friend was in trouble, if not worse since she had tapped into the Kyuubi's chakra as a last resort. The agonising thought of his best friend dying at the hands of someone he failed to stop caused his heart to wrench violently and suddenly, he felt as if his mind blacked out momentarily.
The mental stress of being held back by Zabuza and being unable to help his friend, who was currently losing herself to the beast that lay within her, as well as the Kyuubi's Killing Intent weighing down on him caused Sasuke's brain to release a chakra unique only to his clan.
With a shuddering breath, Sasuke's eyes bled out and turned a bright crimson, accompanied around the pupil by a ring that went through a single tomoe. Everything became clearer and sharp before his eyelids fluttered and he fainted, unable to handle the stress on his mind any further. Kiba cursed and tried to crawl over to Sasuke, but was unable to do so.
"W-What the hell..." Zabuza spoke through gritted teeth, eyes narrowed as he glanced in the direction of Naruko and Haku. He buried his sword into the ground and leaned against it,
"Damn it... Did the seal break?" Kakashi "I need to end this now!"
Neji and Lee slouched slightly as the wave passed by them. They were further away from Sasuke and Kiba and weren't nearly as affected by it, but were still visibly fighting against the overpowering Killing Intent.
Gai frowned and glanced over his shoulder as he felt the Kyuubi's aura once again, a feeling he wished would've never risen again so long as he lived. But alas, something must've happened to Naruko to have caused her to use the Kyuubi's power.
Glancing back to Haruto, Gai noted the lack of care or worry in his eyes for his sister's current state. By his feet, Raiga lay, a large gaping hole in the middle of his torso. His eyes were glazed over and hazy, mouth wide open in a silent scream.
Haruto held the infamous blades in one hand, clutching onto it tightly. Gai assumed that he was unnerved by the Kyuubi's chakra as well, thus his sudden tense disposition. The boy had been four when the monster had struck and had been right there in front of it when it was sealed. To have felt it's awful aura again must have brought back memories of fire and death to him, thus his sudden tenseness. Gai was unaware that Haruto was mostly concerned for Naruko.
"Is this your doing, Haruto-kun?" The man's face hardened considerably when he came to the same conclusion everyone else did. Even more so when it came to the little girl he cared about like he did his students. "Did you plan for Naruko to use the Kyuubi's power?"
"Plan for it? As I told you, I had no intention of meeting you lot. I received word that two of the Seven Swordsmen were after a bridge builder and that piqued my interests enough to come here."
Haruto hid his worry incredibly well, but inside he was panicking for his little sister. Luckily the Kiba were forged incredibly well, or else it would've snapped under Haruto's current vice grip. He desperately wished he could rush over there to help her, but he couldn't. He even had to force himself to stand still, controlling his breathing and reminding himself over and over again that if he could not break character.
He was certain that Itachi would've done the same in his place. So, with an incredible amount of self-control, he calmed himself down, blinked for a second longer than usual as he recollected his thoughts and replied to Gai in an even voice after a moment of forethought.
"But now you're faced with a choice." Haruto tilted his head to the side to look over Gai's shoulder and down the bridge. It was still misty so not much could be seen. "Assist my sister and let me leave, or fight me and possibly allow her to release the Kyuubi, destroying everything and anything in it's path."
Gai frowned deeply at Haruto, disappointed that he would stoop so low. While he may have slaughtered the Uchiha Clan, he had done so with mercy to almost all the members. Many of whom had died not even knowing they had died.
But to use his own sister as bait to get away, whether planned or not, was truly despicable.
"You disappoint me, Haruto-kun." Gai shook his head as Haruto began to leave, "One day your actions will catch up to you, and you will come to regret them then."
Haruto said nothing as he jumped off the side of the bridge, but his thoughts were in a complete mess.
I know, Gai-sensei... I know. But Haruto was relieved that Gai had chosen Naruko over him, mainly because he worried about her but also partially because—had Gai picked him over Naruko, Haruto would've had to detonate the bombs he had planted earlier to distract the man. It was over the top and grand, as well as unnecessarily explosive, but it would've given him enough time to run from a man who could unlock the Eight Gates. Glad that it was the former, Haruto hit the sea in a sprint and quickly took off, not looking back once.