Prologue

[Valley of the end, Shinobi world]

Hundred years in another world before current event

This valley, on the border of the Lands of Fire and Sound, was once the sight of a legendary battle between Madara Uchiha and Hashirama Senju more than hundred year ago; the valley became a scar on the earth itself, the two shinobi that fought here forever etched into the valley by the two statues that lined the waterfall that ran through this place. It is here, in the shadow of these famed warriors that two other shinobi were fighting in a desperate battle of their own.

These two shinobi were Naruto Uzumaki and Sasuke Uchiha; the manipulations going on around them had poisoned Sasuke's mind as he tried to kill his best friend in order gain the famous Mangekyou Sharingan. At the other hand, Naruto was desperately trying to stop Sasuke from leaving Konoha to join Orochimaru, who wanted to take Sasuke's body for his own.

Despite his efforts, however, Naruto was unable to convince his best friend to see error of his ways and had to use more force as their battle reached its ultimate climax; Sasuke prepared to use his Curse Mark-enhanced Chidori while Naruto prepared his Kyubi-enhanced Rasengan.

With their jutsus fully charge Naruto and Sasuke at each other, their jutsus colliding before exploding, which caused severe damage to the statues of the famed founders of Konoha?

Sasuke was knocked back by the explosion, smacking into the statue of Madara before falling to the ground, still alive but unconscious and critically injured.

Fate was, tragically, not so kind to Naruto who has his hand destroyed was pierced though his heart by Sasuke's Chidori and was launched into the lake below, his body further paralyzed by the electricity generated by the lighting-style jutsu; as Naruto fell further down into the depths of the lake he could barely hear the Kyubi's voice as he appeared before the Beast's cage.

"Wake up, you idiot; we're dying here!?" The tailed beast yelled; the Kyubi's attempt to rally her Jinchuriki was a useless gesture, however, as Naruto's were too grave for even him to heal.

"You know as well as I do that we're already dead, Kyubi-chan…" Naruto replied; before the Kyubi could say anything, however, the shinobi said something.

"I was hoping to do something about your hatred someday as well; I guess that's now going to be impossible, however. I'm sorry, Kyubi, for letting you down," the dying ninja smiled; the tailed beast was, naturally, stunned by this. The Kyubi wouldn't have believed what her Jinchuriki just said except for the fact that the look in Naruto's eyes had a serious a look as they've ever been.

"Normally I would have accused someone who said that of lying to me; for some reason, however, I can tell that you're being honest with me… (sighs) Maybe if we had lived that might've succeeded," the Kyubi said as the darkness began to consume her and Naruto.

"I wanted to ask you something, Kyubi, and since we're dying I might as well asks it now; do you have a real name?" Naruto asked while coughing the blood.

This shocked the Kyubi; no one since the time of the Sage of the Six Paths had ever thought to ask for her name, "Since you're not as bad as I thought I guess I can tell you; my name… is Kurama," She said as the last vestiges of life within her and Naruto vanished, but not before Naruto commented on the Tailed Beast's name.

"So you're name is Kurama, huh? I think it suits you. (sighs) Farewell, Kurama-chan," Naruto said as he awaited the afterlife, unaware that he and Kurama would not be so easily die…

[Konoha Hospital]

Few minutes later

Kakashi had just brought Sasuke back from the Valley of End, having found his unconscious body; he had not found any sign of Naruto anywhere and had assumed that he would be healed by the Kyubi and would return to Konoha within a couple of hours.

As a team of medics, lead by the Tsunade, were treating Sasuke for his wounds, which bordered on the mortal level, Kakashi was trying to calm down Sakura, who had arrived at the hospital upon receiving and who surprised her sensei with her reaction.

She was angry... but not at Naruto.

"How could you leave Naruto alone like that, Kakashi-sensei?! You saw what he had to do just to stop Sasuke from leaving; he's probably badly hurt now as well!" Sakura yelled.

"Sasuke was the only one I found, but Sakura; I wouldn't worry him, though. His wounds have always healed quickly so he probably won't be gone for no more than a couple of hours," Kakashi reassured his squad member; what he didn't was that the blonde that they knew will change.

Shortly after dying Naruto arrived in the underworld, where he was reborn as a Baal clan with Kurama still sealed inside his body.

Naruto was surprised, though strangely relieved, to find out that Kurama was still inside him; the Tailed Beast was still bound to Naruto's soul. It didn't take Naruto long to made good on his promise to Kurama, earning his trust and shortly thereafter, as an unintended benefit, full access to his powers.

At that time the Underworld fell into a civil war with the Satan families wanting to continue their families' legacy and fight against the Angels and the Fallen ones while on the other side were many of the remaining families of the 72 Pillars that had been reduced to now just 34 that wanted peace and a new order.

The conflict lasted for almost a decade until eventually five strong devils from five different families all stood together and pushed back the Old Satan Faction and secured the war in favor of the Anti-Satan faction.

Sirzechs Gremory, Ajuka Astaroth, Serafall Sitri, Falbium Glasya-Labolas and finally Naruto bael, himself.

Naruto and Baal Clan at first very reluctant to help his cousin's group to usurp the Old-maou faction from their throne, but after he witnessed what they did to human, finally he agreed to join the rebel as helper.

The civil war had taken its toll on every Devil alive but eventually the Anti-Satan faction prevailed with Sirzechs and Naruto landing the final and deciding blow to Rizervim Livan Lucifer and securing the victory for the new devil faction.

With this the old faction retreated and hid while the Underworld quickly began to change under its new management.

With the leaders gone, the five stepped up to take responsibility of the Underworld and to protect its people and everyone that lived and breathed in their home world.

Before this could continue a problem arose, one that surprised many and shook the relationship between Naruto and Sirzechs.

The position of Lucifer.

Naruto as the strongest and oldest out of the five with his unmatchable essence of power of destruction must be the Lucifer. But Naruto nominated Sirzechs as Lucifer which bring the chaos as the seat of Lucifer should be taken by the most powerful devil in underworld.

Sirzechs although young was a formidable devil as well, though still out of Naruto's league, he was still what considered as prodigy with his application of Power of Destruction.

Sirzechs who at that time still has a very big ego strongly opposed Naruto laid back attitude toward the future of Underworld and challenged him into a duel for the position.

The fight that made entire war look insignificant in comparison and lasted for almost three days straight with neither of the fighters giving either a moment of rest and which shook the entire Underworld to its core. Enormous parts of the Underworld had been reduced to rubble and would take years to rebuild though thankfully no one was harmed after being evacuated to somewhere safe.

After the three days the victor finally emerged. That day despite his great power, Sirzechs learned that his power was still dwarf Naruto that killed the Dragons and Overlords in past and finally he was defeated.

Defeated and now having to watch the seat that should be his cousin's place.

At the other hand, Naruto who was the winner of their fight was visited by Grayfia Lucifuge.

Grayfia was a beautiful woman from one of the Extra Demon families that was seen by many as the perfect female devil. She had beauty, she had brains, and she had power and had an attitude that could keep even the foulest of male devils in line.

She had originally been on the side of the Old Faction but after meeting the ever-smiling and strong Baal she defected and became a powerful ally for the new group.

She told him that she wanted to come with him, to search for her little brother place. She also said that it was her fault that he was getting inside the war and it was her job as older sister to stop him from his foolish job.

Naruto at first reluctant to accept her as his own companion, but after witnessing her feeling and love toward her brother. He took her as his (temporary) servant.

Two weeks after that, both of them suddenly vanished leaving only note that was telling the other they were going to search for another world.

Afterward his leaving the Underworld moved on and rebuilt. The reaming four heroes of the Devil civil war took up the mantle of the old Satan's and became the new Four Great Satan's with Sirzechs being the leader of the four and taking up the mantle of Lucifer while Ajuka took Beelzebub, Serafall took Leviathan and Falbium taking Asmodeous.

Then sometimes later, Ajuka found the secret of Naruto's master and servant spell with the material to make the evil pieces.

With so few pure blooded devil left and half of the 72 pillars now extinct they needed to repopulate the Underworld and somehow Naruto (idiotic) spell was the only way to out of that.

This was where Naruto found himself, hundred years later, when he heard about that rumor…