A/N: This story is based on one of Challenger's challenges. Be warned that it will contain extensive violence and probably lemons at some point. The pairing will be Naruto/Harem since that was the challenge. The ones who must be in according to it are Hana, FemKiba, FemSasuke and FemItachi. Not my favourites (except the first), but I don't have any problem with them either. Also in the harem will be the person introduced at the end of this chapter. Others with high chance of being in the harem are FemKyuubi and Anko. If you want to voice your opinions on the harem, do so in your reviews. Just remember that Sakura, Ino, Tsunade and Shizune won't be in it. AND DEFINITELY NOT HINATA!

Disclaimer: I don't own Naruto or Underworld. There, I said it, don't expect me to say it again.

CHAPTER 1

FIRST TRANSFORMATION

Ten-year old Naruto looked backwards, towards his pursuers, to see if they were gaining on him. They were.

He cursed and tried to run faster. He knew he shouldn't have come outside. Old Man Hokage had told him a thousand times to remain inside during the annual festival held to celebrate Kyuubi's defeat.

However, tonight a full moon shone bright in the night sky, and Naruto could never resist going outside at nights such as this. The full moon always was alluring to him for some reason.

Naruto's thoughts were cut short by a kunai that was embedded to his right leg, thrown by one of his shinobi pursuers. He fell down.

In seconds the mob that was hunting him had surrounded him, raining blows down on him. Naruto managed to turn around and raise his hands in front of him, trying to defend himself. It was futile.

As more and more villagers started hitting him, Naruto knew that they weren't going to stop. That he would die this night. And to think that tomorrow he would join the Shinobi Academy. He raised his eyes towards the moon, the full moon that would soon be the reason for his death. Even now he found it beautiful and alluring.

Suddenly, a red light enveloped him. The civillians and shinobi that were attacking him fell back, afraid that the demon was going to try something against them.

When the light died out they saw that… nothing has changed. Naruto just sat there, unmoving, staring at the moon.

The villagers, still hell bent on killing him, started to approach cautiously, fearing a trick. Nothing happened however. They slowly regained their courage and were once again ready to kill him.

However, Naruto's fate wasn't to die that night. Just before the first person reached him, Naruto started to convulse violently, an expression of intense pain etched on his face. The villagers that were out to kill him once again fell back and watched him, half afraid of what was going to happen and half thrilled with the pain the demon boy was obviously feeling. Little did they know that these convulsions were the prelude of their own deaths.

Naruto started to change. He became slightly taller, his hair turned black and became somewhat longer, his very skin took a very dark colour. His muscles, bones and skin became a lot stronger and, when he started to get on his feet, the terrified mob saw that claws have sprouted from his fingers.

Then he turned his eyes on them. His bright blue eyes have turned to pitch black, even the whites. They were eyes in which nothing could be seen. Not humanity, not reason, and sure as hell not a single shred of pity.

He opened his mouth, which was now full with sharp teeth, and roared. It was a sound completely primal, something a wild animal would make. Then he lunged towards the mob that was hunting him. The predators had just become the prey…

Among the mob hunting Naruto, there were five shinobi. The four were low chunin, almost genin. Only the fifth was of higher rank. A mid jonin of some talent, whose parents were killed by Kyuubi. He was also the one closest to Naruto when he changed.

When the transformed boy lunged towards him, while he was fast indeed, the jonin should have been able to act in time and even counter-attack to such an obvious move. However, his surprise at what just happened, along with the fear that he was feeling in the more primal and instinctual part of his brain prevented him from doing so.

Just as his brain told his limbs to move, Naruto's claws found his throat, opening five deep gouges. As the jonin fell down, his life bleeding out of him, Naruto was already moving towards the four chunin, who were the next closest to him.

The four chunin, already frightened enough, became even more scared when they saw the jonin die so fast. As if Naruto needed an even bigger advantage. They died in seconds, one in the same way as the jonin, one punched in the chest so hard that it caved in, one with a broken neck and one with his head pulverized from being thrown head-first and with ridiculous speed and strength against a nearby wall. Then Naruto turned to the civilians.

From the sidelines, at the top of a nearby building, Hiruzen Sarutobi, Sandaime Hokage and ten of his best ANBU were watching the scene. They were there since Naruto started to change, however their surprise at his transformation prevented them from acting before the shinobi were killed. Not that they were in a terrible hurry anyway.

Now Sarutobi was thinking about the best way to confront Naruto. Or rather, what Naruto had turned into. He raised his hand to stop on of his ANBU from going down there. He was not about to let his shinobi go in such an unusual and, obviously, dangerous situation without first coming up with some sort of plan. Now, if some of those civilians that were always hunting Naruto just happened to lose their lives while he was doing that… Well, he wouldn't lose any sleep over it.

When the last civilian fall down, trying to prevent her innards from spilling out of her slashed belly, Sarutobi and his ANBU jumped down.

Naruto heard them and turned around growling. He took a step forward, ready to attack.

"Now, now, calm down Naruto. It's me, Sarutobi. The Old Man, remember?" Sarutobi spoke, trying to calm Naruto down. He knew that if he attacked, they could easily subdue him, having already seen his speed, strength and the way he moved. Still, Sarutobi didn't want it to come to that.

Naruto lunged.

Sarutobi sighed and prepared to defend himself.

Then a black blur, moving too fast for his eyes to follow, passed in front of his eyes and suddenly Naruto was gone. He heard a crash and looked to the side, only to see Naruto rebounding from the wall he had just hit. Before he could fall down, a black clad figure caught him from the throat, slammed him on the wall again, kneed him in the gut, and, when he doubled over, punched him at the base of the skull.

Unconsciousness was immediate. It also undid Naruto's transformation. While Naruto's features were returning to normal, the figure bent down and took him in its arms. Then it turned to leave.

"WAIT!" shouted Sarutobi. The figure stopped but didn't turn around. "Who are you and what do you want with Naruto?" demanded the aged Hokage.

The figure turned around. One of the ANBU, who was wearing a dog mask, gasped. The figure belonged to a woman of stunning beauty. She had short straight black hair and bright blue eyes that studied the group standing against her without missing a single detail. She was dressed completely in black, wearing black form-fitting clothes and over them a black trench coat. They way she held herself said that she was an experienced fighter.

"I want to help him. I'm the only one who knows what happened to him. Although I don't know the how…yet. I'm also the only one who knows what he needs right now." she answered curtly.

"Well, what is it that he needs?" asked Sarutobi, deciding that introductions and what exactly happened could wait until later.

"It doesn't matter. You wouldn't understand, and I don't have the time to explain to you now. I'll find you tomorrow and we'll talk." she replied with the same tone.

"How will you find me?"

"The boy will tell me." With that, she turned to leave again, deciding that the conversation was over.

"Wait. Just who the hell are you? I've never seen you in the village before." asked Sarutobi hoping that the answer would help him find her. Judging from her previous speed, they had no way of stopping her from leaving, not with all his people gathered behind him.

The woman looked at him over her shoulder. "I'm Selene."

Then she disappeared.