Disclaimer: If I'd written Harry Potter, it wouldn't be the world-famous book series it is today. There's a reason I write oneshots.

This is a sidestory to my other oneshot Manslayer. You'll probably be a bit lost if you haven't read that one.

The Reason Why

Ron stared across the clearing at what was once his best friend, now a stranger. Harry had told him to forget about him, when he'd left, but the redhead had never been able to fully sever the bond of comradeship between him and the Boy Who Lived.

Even if he could hardly see his friend in the figure standing on a branch twenty feet above the ground, reclining on the tree's trunk.

"You wanted to talk to me." The eyes once green stared down at him emotionlessly, as a hand pushed his sleek ebony hair out of his face.

Ron nodded wordlessly. Just once, before Harry left for good.

"No," Harry corrected, looking unconcerned.

"Wha-?" started the redhead.

"You did not want to talk. You wanted to ask me a question."

Oh. Ron bowed his head slightly. "Yes." This was his chance, and now he choked, not able to come up with any of the complicated questions he'd thought up. In the end, all he could say was "Why?"

Why? You had to kill Voldemort - you didn't have to kill them all... How? How could you kill them all, and not even care? The question was almost accusatory.

Harry didn't seem to care. Instead he closed his eyes in thought. A slight breeze blew through the clearing as neither spoke, one waiting breathlessly in hopes of a answer, the other decided whether to give it.

The black-haired swordsman then surprised Ron by sighing. "That's a loaded question you have." Ron had no doubt he was the only person on the earth that could detect the faintest note of amusement in the words.

"Unfortunately," Harry continued. "I can't tell you."

"Can't tell me?" squeaked Ron in surprise.

"No." A pause. "But I can show you."

Ron's world went black.

It was official. Harry Potter despised Dolores Umbridge. He could deal with an ignorant ministry making him out to be a deranged lunatic. He could deal with a stooge for the minister at Hogwarts. He could deal with writing lines into the skin of his hand, even. Harry could deal with a lot of things.

But when the ignorant ministry making him out to be a deranged lunatic sent a stooge to make him write lines into the skin of his hand for wanting to train for a future encounter with a madman, that's where Harry got a little - okay, not a little, a lot - pissed off.

He needed to train. He had to learn to fight. He couldn't rely on the luck that had lasted him this long, not with Voldemort back; but Dumbledore was playing his little game of Ignore Harry and Defense was rubbish.

Only the knowledge that the ministry would use it as evidence to stick him in an asylum kept Harry from screaming out his frustration.

When he finally came out of his thoughts, Harry had no idea how he'd gotten on the seventh floor, but he recognized the tapestry of the trolls clubbing Barnabas the Barmy. What he didn't recognize was the door across from it, and he lost no time in opening it and going in.

It was completely dark. The hair on the back of his neck began to stand up, and instinct took over as he threw himself to the side.

Then the lights came on and Harry saw the blade buried in the door. If he'd been any slower, it would have taken his head off. Realizing with a start that someone was in the room with him, he ducked down just in time to avoid another projectile, shorter but just as sharp.

"Interesting…."

The other studied him, and Harry returned the favor. He was taller than Harry by over a foot and a half, with black hair spilling down to his elbows. Though the other looked no older than twenty-five, Harry got the feeling he was well over that; his eyes, solid amber, held an air of one who'd had seen many years.

"You don't look like much," the other concluded.

Harry twitched, but wisely kept his mouth shut. Some of his oft-ignored instincts - the ones regarding self-preservation - were kicking in due to the presence of this strange man.

"Still…. There's only one reason you could be here. You want to learn to fight, and you've realized the futility of limiting yourself to that useless stick. That's two points in your favor. In addition to that, you dodged the katana and wakizashi. Two more points. Lastly, you have the brains to keep your mouth shut and not piss off someone who could kill you easily as breathing. I think we have a winner here."

Movement from behind gave Harry a split second to move and the shorter blade - the wakizashi, he figured - flew past his head to land neatly in the stranger's hand. The katana did likewise, and he sheathed them both.

"What do you say?" said the stranger, amber eyes glinting. "Choose. Do you want to choose to be trained, and train until you've mastered Himahou-ryu to my satisfaction, or you leave and do not return. This will be your only chance."

Harry didn't have to think long. This was what he'd wanted, right?

"Very well then," said the other, now his teacher, with a smirk Harry didn't necessarily like. "I don't need your name, and you don't need mine. From now on, you call me Sensei."

Ron shifted in the blackness of his mind. He didn't want to contemplate the odds of the prior event happening to anyone but Harry.

It had never occurred to Ron that the change in his best mate could have begun in fifth year. Neither he nor Hermione (or anyone, really) had noticed anything wrong with the boy-savior; his moodiness had been a constant the entire year. He couldn't blame him really, but it had been very trying.

Ron didn't have time to think over the memory much longer, before another got his attention.

"A final lesson?"

"Yes. The last you will have with me."

Harry studied his teacher. There was something to this final lesson that he wouldn't like, he knew.

After over five years of training in Himahou-ryu, Harry Potter was hardly recognizable as the angry boy who had originally agreed to learn. His short, unruly hair had grown out long enough for him to tie it back, and his distinctive, brilliant green eyes - no longer hidden behind glasses - had somehow changed to include the solid amber of his teacher.

Sensei didn't seem to know how to phrase whatever he was going to say next. Speechless was something Harry'd never seen regarding Sensei.


"One last fight. And this time…." The other settled into a fighting stance. "Only one of us lives."

Harry had no idea how, an hour later covered in blood and carrying a dead body, he sneaked unnoticed and unseen from Hogwarts' Room of Requirement to the surrounding forest. The school year was still in session, even if the number of students attending was at an all time low; he ought to have seen someone.

It didn't bother him, though. Later he would be thankful. He hadn't been his most observant flitting through the school he'd attended for six years - after all, Sensei was dead and it was Harry who'd killed him.

Just as Sensei had killed his own teacher. It was a tradition, he'd said before he died.

Harry laid the corpse down on the ground in the forest, and then took out his wand - something he hadn't done in over a year. With a wordless swish of the wand, he set the body aflame. The red-gold blaze lit the forest clearing up like a torch, licking at Sensei's body and sending an unpleasant odor into the air - burning flesh - but Harry couldn't tear his eyes away.

"Funny," he breathed into the night. "Funny that I would shed tears over a man I barely knew… and now with you, my eyes are dry. For in the end you were more to me than Sirius ever was."

The crack of a broken twig caught Harry's attention. A split second later, out of a shadow fell a body with platinum blonde hair, Harry's wakizashi buried in his chest.

"This place is not for scum like you," Harry murmured, turning around to view the now-deceased sod. "In fact…." He cast the body one last look, cast one final spell on the area. "I think it's time I focused my attentions on ridding the earth of you trash…."

He bent over the body, retrieving his smaller blade, and wiped it clean on the Death Eater's robe. Then, hefting the body of Draco Malfoy,Harry Disapparated to deposit his cargo at the Ministry of Magic.

Harry Potter's life as the manslayer had begun.

Leaping from his perch in the tree to the pristine green grass - bearing no mark from the fire from five years prior - Harry watched quietly as his former best friend tossed from side to side, fighting to regain consciousness.

There was no pity in the blue eyes that opened, nothing but grim understanding. Harry liked that.

Maybe... Right before he disappeared, he turned slightly, amber eyes glinting. "See you around."

Ron's eyes widened, but he didn't have a chance to reply. The manslayer vanished without a sound.

There you are. For anyone who wondered how Harry learned to used a blade beyond the pathetic swinging around he did in Chamber of Secrets, here is your answer.

Please review!

Sal