Disclaimer: I don't own Naruto—if I did, I'd be rich—I'm just borrowing the characters for a while, and I'm making no money in doing so. So please don't sue.
Notes: Very AU, pre-timeskip, no bijuu (therefore a Kyuubi-less Naruto), no Uchiha massacre, follows "Fox Moon"…
I hope that you enjoy it!
Haku hated killing. Had his circumstances not been so unfortunate, he might've led a nearly ordinary civilian life. But he had been born with the power to create ice (a kekkei genkai—an unforgivable sin in Kiri) and so in order to survive he had little choice to become a killer.
The effeminate boy sat in the pocket dimension behind the panes of his demonic ice mirrors and unhappily studied his next victims in between volleys senbon needles—both those made of metal and those he generated from his own ice. Two boys, young hunters of the Leaf, sat trapped in his dome of ice. Their squad had the misfortune to get between Zabuza-sama and his latest contract: Tazuna the bridge-builder.
His master, Momochi Zabuza of the infamous Seven Swordsmen, had once been a feared and respected slayer of demons of Kirigakure no Sato. But Zabuza-sama had tried to depose the Mizukage…and failed. That left Zabuza-sama a fugitive on the run from everyone and that worked as a mercenary to try and gain the funds needed for a second coup attempt.
Momochi Zabuza was a monster, a lover of murder and blood, but Haku would follow him to hell and back. Zabuza-sama had saved him from the streets when no one else would and taught him the secrets of ninja magic. The swordsman owned his life and Haku was his grateful tool. Whatever Zabuza-sama wanted, Haku would do, no matter how terrible.
Now two boys not much younger than Haku would have to die…
…Or did they?
If he could use his precise needle skill to place them in a state of false death they would be taken out of the fight. Then he could do the same for their female comrade, who was charged with defending the bridge-builder. And then he could slay the old drunkard while Zabuza-sama kept the dangerous copycat Hatake Kakashi busy, and the contract would be fulfilled. They would be paid, and they could leave in search of the next ugly job.
It was the perfect solution, he thought, as he riddled the Uchiha boy's body with needles in dozens of important pressure points. The dark-haired boy was of the Uchiha clan, and killing him would draw the wrath of the Sharingan upon them. And Haku had a fondness for the blond boy after having met him off the battlefield; he had the sense that Naruto was a lot like him—one who hid a secret shame.
Although, as Konoha treasured those with kekkei genkai unlike Kiri, it was impossible for Haku to guess what Naruto's secret was.
Haku's needles hit their marks and he watched impassively in the shelter of his ice mirrors as the Uchiha crumpled and appeared to die. He tried to warn Naruto away from continuing the fight. Even though he wouldn't kill the boy, the needles would still hurt him and it would take a while for him to fully recover—
Something about Naruto abruptly changed. The clumsy boy who was frightened but determined to do anything to help was replaced with a boy who had a…feral air about him. His stance changed, wisps of chakra seemed to ooze from his skin, the odd whisker-like marks on his face darkened and spread into black stripes, his fingernails and toenails seemed to have turned into claws, his lips peeled back in a snarl and revealed canine teeth so long they were fangs, and then he opened his eyes and glared at Haku with cat-like pupils and blue irises that were bleeding into red.
With an animalistic roar, Naruto charged, his clawed hands shrouded in blue flames—
Haku was forced to dodge to another mirror as the boy slammed his fist into the one that Haku had previously hidden in…and cracked it. The ice-user tried to cripple Naruto with more senbon needles but the feral child was much faster and much more agile than before. The blond moved like a demon trapped in a human's skin.
Then Naruto shattered one of his mirrors—something that his Uchiha comrade hadn't even come close to doing. And then he did it again, and again, and again. With his mirrors a failure and with his chakra stores steadily draining Haku released his hold on them as he dove back into the real world in a bodily attack on Naruto's back—
His feral foe whirled around and caught Haku by the wrists, squeezing them and digging his claws through the fabric of Haku's kimono-like sleeves while the blue fire seared his skin. Lashing out with his foot Haku was able to free one of his hands long enough to form the one-handed hand seals that generated ice needles. The ice weapons turned the wild boy into a pincushion which allowed Haku to break loose and get a little distance.
…Who is he?
The ice needles didn't buy him the time that he thought they would. Naruto shook them off in a shower of half-melted ice shards and then was on Haku again. The demonic boy darted in again and again, slamming Haku with punches and slashing at him with his claws.
…What is he?
And then with one final punch he shattered Haku's porcelain mask.
Is this his secret shame?
Naruto's demonic red eyes went from furious, to confused…and betrayed.