This is a response to KyuubiWindscar's Challenge:

Naruto: The Leech

A story that changes how we think about bloodline copy/stealing bloodlines. This one involves Naruto having one of those, but when he steals the bloodline, it kills the victim. That and, once he starts, he gets an uncontrollable urge to get more. Then, his urge becomes a powerful hunger for every bloodline in the world. I only have a few conditions, which are:

1. Naruto must start off somewhat innocent before going wildly chaotic with his hunger for new bloodlines.

I say this because it is an aspect of the bloodline. Without it, there wouldn't be enough conflict for a real story.

2. If Naruto steals the Sharingan, he finds a way to do it without killing the person

This is to challenge you as a writer, and to avoid any and all Sasuke bashers. Make it believable.

3. Naruto can't just go off stealing bloodlines

By that, I mean that he can't get some unavoidable order from the council that binds him to get every bloodline from the rest of the world. Which brings up the next condition

4. No one can know about Naruto's bloodline for fear of his own safety

He's slowly becoming a monster, and he is the only one in the world that can do what he does. It is really smart for him to have everyone know about it?

5. You have to have him steal at least two original bloodlines you created yourself.

This is just for the fun of it. Go wild with this one.

6. You have to come up with a pretty creative, as well as believable way to describe Naruto's bloodline.

I just don't want this idea to go to waste in some idiot's hands by messing up the most integral part of the story while he/she writes a really great story otherwise.

Other than this, it's fair game.

Note- this response may end up screwing the rules. Oh well, I'm LightningHunter, a self-proclaimed dick and this is what I do.

For the actual leeching, I couldn't work out what method would be best. I was originally thinking kind of like Venom or similar, but then I was pretty sure that'd been done enough times. So, I did a classic blood drinking Dracula thing, after all, it's called a blood line for a reason.

I sent a message to Windscar a while back about this fic, asking if it was alright. I don't know if there's been another response. He never replied, and since it's been over a month or two, I'm gonna assume he never got my message and was on a fanfiction break. Since we usually get on quite well (he beta-reads Zero), I'm also going to assume he didn't mind.

Chapter I- Manifestation

"So," said Haku. "Kill me."

Naruto's grip tightened, then slackened on the kunai he held in his hand. He had been full of such wild happiness when he first left Konoha for this mission. Sure, it had only been a simple C-rank, a mission to protect an old man from highwaymen and bandits, but it had been his first real mission, outside the village where he could finally see some action.

From the first day, it'd gone to hell. They'd been attacked by ninja- not bandits- and Naruto had frozen up, getting poisoned and nearly getting killed had it not been for Kakashi- and dare he admit it- Sasuke.

Then soon after, they'd encountered an even more powerful ninja. Zabuza, the Demon of the Mist. He'd first written the man off as some creepy joke, with that oversized sword and the lack of eyebrows- but then had come the mist, and then he'd captured Kakashi, and Naruto had realised truly just how outclassed they were.

Naruto's tactic to free Kakashi had worked- on luck. Zabuza had simply underestimated them. If he'd actively sent his Water Clone after him, Tazuna's head would've been delivered to Gatou- the man behind the ninja and the poverty of the Land of the Wave.

They'd trained hard, knowing Zabuza would be back with his fake hunter-nin friend. And on that day, Naruto had been late to the bridge. It had proven to be incredibly beneficial, as he'd been able to return to the household and save Inari and Tsunami. And then, it was back to the bridge, where he'd found Sasuke trapped within walls of ice-

Sasuke had been killed, protecting him. Then, what exactly had happened? Naruto didn't understand it himself. He had felt so angry, bestial rage pumping around his body so hard he felt he was on fire, and then, he'd gone berserk.

And he'd brought himself back, when the mask had shattered and he'd identified Haku to be the girly-boy back in the woods.

Haku was the one who'd told him true power comes from protection. Haku- was he really evil? He was a killer, but only to receive acknowledgement from the only person who'd showed any kind of affection for him. It ran dangerously close to Naruto's past, save of course, Naruto had had the misfortune of being the container of a demon that'd once nearly wiped out the entirety of the Land of Fire.

But Haku of course, seemed to have a bloodline. He shivered- the power he'd seen. The power had killed Sasuke. It was a power- that he had to have.

Where did that come from? He asked himself, but his mind was lost as he thought of the bloodline that had been powerful enough to kill an Uchiha, those who held the revered Sharingan.

Naruto's thoughts were so concentrated on Haku's bloodline he had not realised he had begun to drool. He shivered- but not in fear or awe, out of anticipation- greed. It'd be his power, his own.

An incredible Hunger filled him. The kunai fell from his hand, and he looked straight into Haku's eyes. The crimson eyes had gone, but now, these eyes seemed just as inhuman to Haku.

"The blood is the currency of the soul. And your powers shall be mine."

He pounced on Haku, shoving him to the ground. His hands clutched at his shoulders, and Haku's head slammed hard against the ground. Naruto's left hand shoved his chin back, and his right hand tore the cloth around Haku's neck till it was completely bare.

He lunged forwards with his teeth, and bit down on Haku's throat, tearing viciously, and lapping at the blood as might a cat. No, he could not drink the blood randomly splashed off a wounded man, he had to drink the blood as the heart made its final contractions, and the body came to die. The blood of the last few drops of life. He did not notice anything change when he drank the blood, but remained so transfixed on his meal that he did not even notice when Haku died.

Soon, he awoke from the Hunger. He struggled to his feet, eyes wide, shocked- God above, what had he done? He'd killed a man- by tearing his throat out! He'd drunk his blood- he was a fucking cannibal!

Naruto struggled to the side of the bridge, and vomited over the edge. It made him feel like dying, but he continued to force the blood out. His hands wiped his mouth clean of any blood or vomit left, but still, something told him now, that vomiting would not turn him back of the path he'd stepped onto.

He had already leeched Haku's bloodline, and now it resided in his veins.

Naruto spat into his palm, and prodded the reddish saliva with a finger, trying to see if that power did indeed live within him. The saliva froze.

The Hunger grew. More, more, more, it urged him. He felt so hungry, and something told him ramen would sate him no longer. But like with ramen, with that first meal, he felt as he did after he'd polish off one ramen bowl- a mighty appetite grew and he could devour as many bowls he could get.

His sustenance would now be provided like the bloodlines, and if Haku's bloodline had told him anything, it was that they tasted good.

Naruto shook his head frantically. What was he thinking? He'd just fucking tore a man's throat out, and now he was contemplating to do the same thing again?

And then a thought appeared, no matter how hard he tried to put it out of his mind. The blood of the last few drops of life still resided in Sasuke's arteries, no?

He fought the urge. He fought it with all his strength. But just like he could not resist another bowl of ramen, he could not resist another bloodline.

Naruto began to walk towards where he knew Sasuke's body to lie, dragging each foot as though it was a chore, his arms limply by his side. He licked his lips, anticipating this feast. After their accidental kiss, he'd sworn to himself that never again would his mouth ever go near Sasuke. Well, times change.

Then he saw something that caused him to stop. He saw Sakura.

She was there, on her knees, crying over Sasuke's corpse. And then, Sasuke's eyes opened.

The Hunger urged him to simply deal with the girl and the old man, and then take down Sasuke. It wasn't as though he was in any condition to fight back.

Naruto was only sickened by his own thoughts. He bit his own lip, hoping the taste of his own blood would sate the Hunger temporarily as he stumbled away through the remnants of the mist. He had to get away. How could he look Sasuke in the face now, when he'd just been contemplating murdering him in cold blood?

He found Kakashi further up the bridge. The man was panting heavily, low on chakra. Zabuza's corpse lay nearby, and the bodies of ruffians lay around him. An entire mob still waited, a short man standing behind them.

"Go on!" The short man urged them. "He can barely stand now! I'll double the payment for whoever brings me that head!"

The ruffians had begun to charge, but then they saw a small army of orange-clad ninja approaching. Normally, they might have still attacked, but there was a haunted look in the boy's face they'd never seen before in a child- or any other person.

"Hey!" Naruto didn't turn around, but he heard Inari's voice, and then the cries of more villagers. The ruffians retreated, heading back to the boats they'd boarded the bridge from, leaving the short man alone.

Kakashi simply filled his hands with shuriken. He barely had to aim, and the short man was soon dead.

Morale was good in the majority of Team Seven as they headed back on the road to Konoha. Kakashi had watched his students begin to mature. It might be only a few steps on the path, but it was a start. They'd witnessed death; come perilously close to seeing it in a teammate- or receiving death- and Naruto had even made his first kill.

Well, Kakashi wasn't sure about his mental state just yet. The boy seemed as cheery and hyper as ever, but occasionally Kakashi had spied him, his face unsure of something. And even less frequently, Naruto would send Sasuke guilty looks.

But why did Naruto feel guilty? Did he blame himself for Sasuke's near-death? Or had he felt responsible for it occurring in the first place?

But Naruto seemed unsure of himself, less confident of battle. Why? Kakashi had heard him mutter to himself about how he "couldn't lose it again". Lose control? Was Naruto afraid to unleash the power of the Kyuubi once more?

He'd seen Haku's body. The neck had been mutilated, and although he wasn't sure- it looked vaguely like someone had used their teeth to tear it apart. Had Naruto gone completely under the control of the Kyuubi and plucked Haku's throat out?

Kakashi removed his trusty Icha Icha Paradise from his pouch. It'd be a welcome distraction. But he made a note to consult the Sandaime immediately when they made it back to Konoha about Naruto's state.

But he was wrong.

Naruto was looking at Sasuke with the guilt of knowing he'd nearly killed him himself. Even when he'd found Sakura and Tazuna, the Hunger had been driving to crush them if they tried to stop him, and feed from Sasuke anyway.

But what was this Hunger? Was it his own? Or was it the appetite of some other Beast, perhaps the demon that he knew to reside in his mind and soul? But even so, he possessed the bloodline of Haku. He had practised with it, a little, sneaking off now and then under pretence of wanting to scout ahead. Admittedly, he didn't want to use it, it felt like he was-

Then why was he practising with it if he had did not want to use it? Was this the Hunger, simply taking him over with subtlety? He had to do something. He had to talk to someone, who could understand him.

Could he speak to Iruka? No, no, no. Not Iruka who'd said Naruto was nothing like a beast. How could he let him down now? How could he tell Iruka that he'd tore a man's throat open and drank his blood, absorbing his bloodline in the process? How could he tell Iruka that he'd been more than willing to kill Sasuke, and even if for a moment, considered harming the man they'd been assigned to protect, and Sakura-

Naruto could barely look at her. The Hunger was primitive, animalistic, and yet it still felt natural. Like a human growing in the wild without society, it was free. A free man; free to do whatever it wished with no morals to stop himself. And so the Hunger often urged him to feed off Sakura as well, aware it would not get the same satisfaction of eating one who possessed a bloodline, but it was assured it would be worth it.

Maybe her blood will taste like cherries? The Hunger whispered to him.

He walked, barely conscious, so lost in his mind. Naruto was scared, no, absolutely terrified out of his mind. This was not like dealing with the Kyuubi, which he knew was locked so tight away that the Yondaime had killed himself to do it.

He was dealing with something he knew nothing about.

"And we'll stop here," said Kakashi.

Naruto would've gone on walking without noticing had he not walked into Kakashi. They were standing outside a roadside inn. It was a foreboding place, dull, grim, high trees blotting out the sun and casting it into shadow.

"Where are we anyway?" Sasuke asked, regarding the place with suspicion, his hand going dangerously close to his shuriken pouch.

"We're just going to stop for lunch," Kakashi said. "Anything's better than our crappy rations. Come on then, my treat. I figure you guys deserve a little reward after your first big mission."

"Kakashi-sensei, it looks really creepy," said Sakura, watching the building with hesitance. "I mean seriously, look at the signpost. It's called the Inn of Ill Omen."

"Sakura, there's no need to judge," said Kakashi. "And I for one, am certainly rather hungry. What about you, Naruto?"

"Oh yeah," Naruto said, with a strange grin. "I'm starving." The other three did not hear the unnaturalness in his voice.

Kakashi pushed open the wooden door, and beckoned the others in. The place was dimly lit, and there were only about three people there, the innkeeper, a woman and a jumpy old man who was watching them fearfully as though he thought they were there to kill him.

Their sensei ordered them lunch and the innkeeper set about to work. After several painful grumbles from Naruto's stomach, four cooked meals were placed in front of them.

Naruto devoured the food with a sudden viciousness, quicker than he had ever eaten before. It was almost as quick as Kakashi, the genin had looked away briefly, and when they looked back, Kakashi's meal was eaten and he was readjusting his mask.

"Naruto, be careful, you might get indigestion," said Kakashi.

"You just ate even quicker," Naruto said, between mouthfuls, and Kakashi shrugged.

But no matter how much he ate, it did little to satisfy the Hunger that lay within him. He finished his food, but the Hunger dismissed it as a small snack. The Uchiha's blood shall make a finer feast.

"What are you looking at?" Sasuke asked.

Naruto almost jumped, he hadn't realised he'd been staring at Sasuke. "Well," he laughed nervously. "I was just wondering if you were going to finish that."

Sasuke watched him suspiciously as he moved his plate a bit closer to himself.

No, Naruto had decided now for good. He couldn't tell anyone about this Hunger that resided in him. How could he? Not to mention the village. He'd been doing his best to prove he was no monster.

Yes, it was for the best, really. What they didn't know wouldn't hurt them. He wouldn't do it again anyways, and besides, he got a cool bloodline out of it. But then Naruto realised if he didn't tell anyone about the Hunger, how could he explain away a bloodline he certainly didn't have before?

Keep it secret. Keep it safe. The Hunger whispered to him. Only reveal it to opponents you shall kill. Dead men tell no tales. And reveal it to opponents you shall feed from.

That made sense, apart from the last bit. Naruto had already decided he wouldn't feed from any more people. One day when he was a jounin or something, he'd have to kill people on missions and stuff. And then, what could be more useful than a trump card? The bad guys would think they had him, when he, the hero turned the tables and trapped them within ice mirrors.

He grinned to himself. What a brilliant plan. Even Sasuke probably couldn't come up with anything better.

It had been a long day. They'd made it into Konoha around four or five and then Kakashi had made a detailed report to the Hokage. Since the Land of Wave would begin their recovery, Tazuna had promised to pay whatever Konoha deemed suitable compensation for lying about the mission. That had meant Naruto had been given a fat envelope with his pay, more money then he'd ever held in his life.

Then he'd seen Iruka-sensei who'd taken him out for ramen to celebrate his first big mission. Naruto had polished off five bowls, but still, the Hunger had not been sated. He knew it now. It would never be settled until he fed off another bloodline-user.

Well, it'd just have to get used to being hungry for eternity. He was no monster.

"So, you going for a sixth bowl, then?" Iruka grinned, finishing his second.

Naruto patted his stomach. "No way, I'm full," he lied.

"Alright," Iruka reached for his wallet, but Naruto stopped him.

"I'll get this. I've got quite a bit of money because of the mission," Naruto said, going to get his trusty Gama-chan wallet.

"Then save it," said Iruka. "Relax Naruto, I'll pay."

"Look, I don't really care who's paying as long as someone pays," said Teuchi.

Iruka handed over a few notes and told Teuchi to keep the change as he and Naruto rose from their seats. They left the stall, and started to walk down the road. Above them the sky had grown dark. "Tell me, Naruto. How do you feel about your first kill?"

"Strange," said Naruto.

"Did you enjoy it, then?" Iruka asked.

Naruto shook his head. He was lying. He knew deep down, a part of him, close to the Hunger, if not the Hunger itself, had enjoyed it. It had been tasty, after all.

"Do you feel any regret?"

"Yeah," he replied.

"Sadly, Naruto, killing is often something that will just grow easier," said Iruka. "But I know you're not the sort of person to enjoy killing and doing so with no remorse."

"What'd you mean sensei?" Naruto asked. "I'm a ninja, we have to kill-"

"That's true," said Iruka. "But enjoying murdering someone? Taking pleasure in the deaths of others? That's not you Naruto. I told you before, didn't I?"

Naruto looked confused.

"You're nothing like the beast," said Iruka, and dare Naruto think it? Was that pride in his voice? "You're a soldier, but you're also a man, Naruto. And I have faith in you."

Naruto grinned up at the man. "Thanks, sensei."

"Don't mention it," Iruka replied. They came to a stop outside the block of flats that Naruto vacated. "Well, see you, Naruto."

"Yeah, see you, sensei!" Naruto chirped as he headed into the building. As soon as he entered the dark corridor and Iruka was well out of earshot, he smiled to himself. "Hear that?" He asked himself. "I'm not a beast. Not a monster. Not a beast. Not a monster." His mantra continued even as he made it to his door, locking it behind him as he kicked off his shoes.

"Not a beast. Not a monster." He continued, as he changed into his pyjamas, too tired to do anything else but sleep, even if he was turning in early.

And as he collapsed onto his bed, his mind was assaulted with images of watching the terror break out on Haku's face as he'd been knocked to the ground. He recalled the smell. A part of it had been sort of flowery, that cross-dresser was probably wearing perfume or something, but he remembered the thick, intoxicating fear that had been rolling off Haku. It had smelled better than any perfume.

And he remembered the taste of the blood.

But he wasn't repulsed.

It had tasted fucking delicious.

He'd once looked up what blood was when he was younger, trying to find out what bloodlines were when he'd heard other academy students talk about them. He never found out what a bloodline was, but he'd learnt the textbook definition of blood; a bodily fluid used to deliver necessary substances and take away waste products.

It mentioned not how it was the symbol of life force, how it was the currency of the soul, and the container of those glorious, delectable bloodline limits.

Once again, he began to drool.

Sasuke wasn't the only one with a bloodline in the village, was he? There was Hinata's family. He knew little about what it was, but if they had such a big family, they wouldn't miss one, would they? Maybe there'd be an old or sick one, and if he was careful how he bit, he could pass it off as natural causes.

He climbed out of bed, in a trance. His bare feet took him to the window, and he opened it wide. Cold air struck him in the face, but it was not enough to break him out of the haze that had seized control of his mind and body.

Naruto licked his lips. Where were the dwellings of the Hyuuga Clan? It'd be in the richer district of the village, of course. It couldn't be too hard to find.

He walked up the side of the building. That chakra control exercise Kakashi-sensei had taught them was pretty useful. Naruto soon stood at the top of the tower block, arms outstretched. There, he could see it in the distance, the collection of buildings that made up the compound vacated by the Hyuuga Clan.

Naruto sprung across the rooftops. If any ninja were patrolling, they did not see him as he ran, chakra providing all the support he needed.

If anyone had seen him now, they would not have recognised him. Wearing nothing but plain white pyjamas, his hair windswept- and his face resembled a beast. No- even Iruka would not have recognised him.

He leapt through the air. Sometimes he'd miss the roof completely, landing in the empty roads of the sleeping village. Such a fall might've broken bones or torn flesh, but it did not faze him in the least. A bestial laugh escaped his lips, and he sprang back onto the roofs without a break in pace.

The Hunger pulled at him, and Naruto could not think about what he was doing. Too much thinking already meant the Hunger had used him till he was unable to think at all, susceptible to commands. It would take more than the absurdity of this now, running barefoot in his pyjamas to hunt one of the members of the most powerful clan in Konoha, to break him out of this trance.

Soon enough, his bloodied feet brought him in front of the Hyuuga Clan Compound. There were a few guards at the gates, but they were half-asleep, bored, their bloodline not even activated. The last incident that occurred with the Hyuuga was well over several years ago, after all. Naruto climbed over the wall, not making a sound as he headed to the central building inside.

He slipped into the shadows, although if someone had looked directly at him, they would have seen him. The white clothing was not ideal for stealth, but in the pale moonlight he looked like a devil or ghost. Still, he continued on his way till he stood outside a window of a room- a bedroom.

A long-haired girl was fast asleep inside. Perhaps she was Hinata's sister or cousin. But doubtless she possessed the bloodline of the Hyuuga, regardless of her relation to Hinata. She rolled onto her back in her sleep.

Naruto pressed his face to the glass, a wicked smile on his face. And then as the girl turned around to look at the window, he realised she hadn't been asleep.

She screamed.

Naruto was gone. He was well out of the compound by the time the alarm had been raised. And when the Hyuuga had finished scouring the grounds and began looking outside in the village, he was already home.

The Hunger's control released, and Naruto fended it away harder than ever. He lay on his bed, mouth open in silent screams. Now he realised just how close he had been to feeding, he was determined all the more to restrain the Hunger that had come so close to seizing control.

He curled up into a ball, shaking slightly. His hands covered his mouth, as though by doing so they might stop the teeth that had been Haku's bane and would have brought death to a Hyuuga girl had she not have been unable to sleep that night.

And from his mouth, a muffled sentence sounded.

"Why am I such a monster?"

AN: Hope you enjoyed it.

I thought it was quite fun, myself.