Disclaimer: I don't own Naruto (obviously), I'm making no money on this, so please don't sue...
Notes: AU, post-Valley of the End. What if Kakashi caught up just in time and caught Sasuke before he fled? And what if the events of the Kyuubi's defeat were a little different?
This story is a work-in-progress; updates will be sporadic at best...
Hatake Kakashi had been in many battles and seen many amazing things in his career as a ninja. He was the son of Konoha's White Fang, a great ninja who had ended in disgrace. He'd studied under Konoha's Yellow Flash, now Konohagakure no Sato's Yondaime Hokage. He'd been gifted with a Sharingan eye from his deceased friend and teammate, Uchiha Obito. He had lived through war. He had lived through the attack of a terrible demon.
However, in all his wide and varied experience, he had never witnessed anything like this.
Crouched at the foot of the memorial statues in the Valley of the End were two of his three students. One was distorted almost beyond recognition with gray skin, claws, long gray hair, and freakish wing-like webbed hands sprouting from his shoulder blades. The other was completely covered in demonic crimson chakra that formed a sort of armor in the silhouette of the fox monster he'd last seen thirteen years before, his eyes red and slitted, whisker marks wide and black on his cheeks, fangs bared, and claws flexing. The gray one had gathered a fistful of crackling lightning that spewed tainted black sparks. The fox-shrouded one cradled a swirling sphere of raw violet chakra that was edged in a red aura.
It was a twisted, terrifying replay of their earlier duel atop the hospital back in the village. That time he'd been able to stop them. But this time, as he raced over the surface of the lake towards the statues and the waterfall, he couldn't stop them. At some signal only they were aware of, they lunged at each other and smashed their attacks together.
The light, the noise, and the wind generated by the blast was incredible. It took all of Kakashi's skill and strength to keep from tumbling end over end to the other side of the valley. Poor little Pakkun, his favorite Summon, was forced to cling to Kakashi's pant leg with his teeth to keep from being swept away by the explosion. Even with Obito's powerful eye, he couldn't see a thing at the eye of the storm.
And then it was over.
Desperate and dreading what he would find, Kakashi dove through the misty curtain of the ruined waterfall. Uchiha Sasuke was still standing. Uzumaki Naruto was not. Kakashi struck quickly, a sharp blow to the back of the neck, and then Sasuke wasn't standing either. Both lay limply on the stone ground, soaking wet and stripped of their monstrous forms.
"Why'd you knock him out?" Pakkun asked, poking Sasuke with a tiny paw.
"I'm not interested in fighting him all the way home," Kakashi sighed and bound him up tightly with wire. "After that stunt I don't dare trust him."
When Sasuke was restrained to his satisfaction, he slung the unconscious boy over his shoulder and moved to inspect the other boy.
Naruto looked dead. He lay so still that it was hard to see him breathing. It was downright unnatural to see Naruto be so still. But by some miracle, he was still alive. With a lot of awkward wrestling, Kakashi hefted his orange-clad student over his other shoulder.
Wayward students both in hand, Kakashi turned to dismiss his canine helper. "Thanks Pakkun."
"No problem." Pakkun waved a paw. "See ya!" Then he vanished in a puff of smoke.
Sighing, Kakashi left the ruined waterfall and the smashed statues of the Valley of the End behind as he started the long run home.