After thinking things through, I realised that this idea might be interesting for someone to adopt, but if anyone wants to put their own spin on it they are more than welcome to.
A New Devil's Marvellous Adventure
Standing in front of a swirling vortex was a tall silver-haired man, wearing a red trench coat with a sword on his back, holding another sword in his hands, with a two-sided amulet wrapped around the handle, guard and blade, a female voice called out to him, "Are you sure you want to do this Dante, I mean, it's your father's sword and your mother's amulet?"
Sighing, the man looks towards the speaker, "It's the only way Lady, doing this not only stops the vortex, but stops demons and other beings from trying to get Forced Edge, along with the amulets, it's the only way, I'm sure my old man along with my mother would've done the same thing if something like this happened to them, hell, he sealed his powers into his sword and closed the gates to the demon world himself with my mother's help, besides, you never know if my brother is still out their, so this is killing at least three birds with one stone."
The woman with him still has doubts, "But what if someone finds the sword on the other side, it could be anyone."
With a wave of his hand, he replies, "Relax, this sword's power will keep it all sealed, kinda like a black hole, sucking and holding everything together until it's settled, then sparda will be sealed as well, no worries."
Before she could say anything, Dante threw the sword into the vortex like a javelin, causing the portal to close in on itself, vanishing from the face of the earth, all the while Dante thinks to himself, "Mother, Father, while I may no longer have your sword and amulet, I'll always have you in my heart, because even a handsome devil like myself may cry."
His friend, Lady moves towards his side, placing a comforting hand on his shoulder since he gave up something precious to him, hoping he did the right thing.
At another point in time, in another dimension, years after the sealing, was the Fourth Shinobi War, with 2 teens fighting a single woman with horns.
The two managed to release everyone from the Shinju tree, allowing them to evacuate from their fight, though the woman was angry at the lost of chakra, causing her to fight even harder, luckily, with the help of the boys teammates, they managed to seal her away in another dimension that the woman created, along with her creation that was filled with her dark ambition.
But there was one problem, the moment the two were sealed, the rabbit goddess flung the blond boy through a portal as a last act of defiance, with his pink haired friend yelling out his name, "NARUTOOOOO!"
Inside the portal
While "travelling," the blond teen known as Naruto was floating through a strange and unknown place, with bright flashing colours, suddenly he catches a glint of something spinning towards him, "What the hell is that!?"
The exhaustion of his fight with not only Kaguya, but Madara, Obito and the war really pushed his stamina to the limits, now he was tired, bruised and aching, until the object got close enough for him to see a strange sword approaching him, that is until he finds the sword embedded in his chest, he was too exhausted to move let alone dodge out the way.
His eyes widened, due to the sword hitting him, it made him slow down enough to exit the portal, he could feel his energy slowly leaving him.
New York Central Park
It was night outside, the only ones out were a few couples and nighttime animals here and there, though the couples were on their way back to their places, never noticing something landing in the trees. (A.N. Whoever said Naruto's "landing" had to be loud and explosive.)
Laying on the ground was Naruto Uzumaki, the sword still stabbed in his chest, his eyes half-lidded, as though his mind wasn't there.
At this moment, Naruto was laying in his mind, due to Kaguya's interference, Kurama was removed from Naruto, but thanks to Haguromo's help, Naruto still lived, but now the leftover tailed beasts chakra from the others were slowly ebbing away trying to heal him, but because the sword wasn't removed, the chakra couldn't do anything.
Though standing over Naruto was a regal looking man, wearing a purple Victorian style outfit, looking at the teen in front of him, "While I commend Dante's sacrifice of my sword and his mother's amulet, he may have just past on my legacy to someone more ideal, if what his memories tell me, along with the leftover energy of those tailed beasts he'll possibly become a full devil, like myself, if he wants to accept my power."
The regal man took a knee, getting closer to Naruto, though at this moment Naruto was too weak to do anything, except look towards the man, hearing everything the man said, "Please listen to what I have to say young Naruto, while I may not be human I have come to accept them as apart of the world, I even fell in love with one, showing that even a devil has a heart, I protected the humans by going against my own kind, now I stand before you, asking you to take my power for your own, become a devil yourself in order to protect others, if you do this you'll live, because you see, my sword is still in your heart, the only way for you to live is by becoming my successor, please, I can not let a human die by my sword."
Hearing the devil say such heartwarming things, Naruto couldn't believe someone was putting their trust in him and a devil at that, granted he would die because of the sword in his chest, but the devil gave him a choice, to live as a devil or die as a man, thinking things through as quickly as his weakened body can, Naruto slowly nods his head.
The devil nods back in understanding, "Remember this Naruto, that even a "Devil May Cry" when they lose a loved one, so take care my son."
Hearing the devil call him 'son,' made Naruto happy, granted he had a father, but now he has two fathers, "Before we start Naruto, know that this will be painful, once my power enters you, along with the tailed beasts chakra, both just may overload your chakra network, destroying them completely, but, because you'll be a devil, you'll still live and heal from it, but you'll not be able to use your chakra."
So he had one more choice, lose his chakra and have it replaced with his devil powers, or keep his chakra and lose his life as well, "Whatever, I agreed to it at the start, so I may as well continue with this, since I am Naruto Uzumaki and I don't back down."
With another slow nod, Sparda knows Naruto accepts the deal, standing back up, Sparda moves back slightly, holding one hand out towards Naruto and the other towards the leftover chakra, then starting the process, the tailed beast chakra passes through Sparda and enters Naruto, causing Naruto to start shaking in pain, as though he was being electrocuted, but the power rushing through him now manages to get Naruto to find his voice.
The power started changing his appearance, turning his skin to lighter tan, his hair went from sun-kissed blond to silver white, his body began to become stronger and heal rapidly, giving his body a lean muscular look, he became taller, closer to Sparda's height, his whisker marks were now fainter, almost like you couldn't see them unless you were looking for them, his eyes changed to a more lighter colour, instead of a deep sea blue colour, they were now a bright cloudless sky blue colour, his canines became slightly more fang-like.
His face became more angular, losing his baby-fat, making him look more handsome.
As the process was nearing completion, Naruto and everything became surrounded by a bright light of white, blinding him and knocking him out, during which Sparda finished things off by giving Naruto knowledge of his sword techniques, though he'll need a catalysis to unlock Forced Edge's awakened form, but Naruto wasn't ready for that, yet.
He also gave Naruto the language part of being a devil, meaning that he'll naturally know mans language. (A.N. Got the idea from Highschool DXD.)
Suddenly, Naruto opens his eyes, his body already changed, due to the power flux, his jacket and shirt was burned off, showing his lean body, sitting up, Naruto looks around, wondering where he was, feeling slightly confused at everything around him, slowly standing up to get more bearings, he rubs the back of his head, "Okay, this place is definitely not the Elemental Nations." Noticing his voice was deeper.
Suddenly, in the corner of his eye, or just under it, he noticed something, "Huh!?" There sticking out of his chest was the sword known as Forced Edge, or the sword so powerful that it was named after it's original owner, Sparda, "Well, this is annoying."
In his confused state, his mind hasn't caught up to what was happening yet, but it was slowly getting there, "WHAT THE HELL, WHY DID I SAY THAT WITH A SWORD STICKING OUT OF MY CHest!?" As he quietens down, he realises that it's not quite as painful as it should've been, placing both his hands on ether side of the blade, he completely removes the sword from his chest, a spurt of blood exiting him, though when the blood lands it disappears from sight.
Looking at where the "opening" should be, all Naruto saw was a line of blood but nothing else, "Okay, that is both awesome and weird at the same time, I guess the old devil was right about me, though I still feel weak, but that's might be because of the chakra network."
Grabbing Sparda's handle, removes the amulet wrapped around the sword and knows the jewellery was important to Sparda, so Naruto hangs the amulet around his neck, Naruto then subconsciously places the sword on his back, where it naturally hangs somehow, until Naruto felt a slight burning sensation, suddenly in a quick flash of light the sword vanished, leaving a tattoo on his back. (A.N. There has to be at least SOME reference of the DMC reboot.)
Looking behind himself, noticing the swords was gone, for now, Naruto shrugs his shoulders, "Well at least I won't get in trouble for carrying a weapon in an unknown place like this, but now that I'm here, what should I do now."
Trying to think of something, Naruto was interrupted by a voice behind him, "If you have no ill intentions, then maybe I can help you."
Turning around, Naruto noticed a man wearing strange clothes, floating down to meet him, holding his hand out towards him, "Greetings young devil, my name is Doctor Strange and I believe we have somethings to discuss."
Naruto, being who he is, shakes the man's hand, not really caring about the devil part, puts his hands behind his head and replies lazily, "Whatever you say Doc, lead the way." Knowing that the man before him was a good guy because of his Negative Emotion Sensing ability, no doubt from the merging of both Sparda and the Tailed Beasts chakra.
As the two were passing through Doctor Strange's portal, they fail to notice a pair of green eyes watching them in curiosity, "How is it that person has such dark powers yet feel light at the same time." The person couldn't help but feel a strange sense of puzzlement at this new being.
At the moment, while Naruto was walking with Strange he couldn't help but feel that from now on, things are going to become even more exciting on his new adventure.
There you have it, Naruto/Sparda in the Marvel world, no Rebellion sword or Yamato, just Forced Edge and the amulet, I figure Doctor Strange would sense Naruto and try to help him, since being the Sorcerer Supreme, he would have something to see if Naruto was a threat or not to the world.
I can also see Naruto opening his own "Devil May Cry" place, doing what Dante did, though being more like a Private Investigator, or something.
Though because of his new devil power, he'll attract the demons of the Marvel world, instead of the DMC world.
As for Pairing(s) it's anyone's choice, though if anyone wants Naruto to be apart of the Avengers from time to time, I can see Naruto and Tony hanging out and having fun, drinking and flirting with girls here and there, since Naruto is a devil now he would need something other than fighting to calm his devil needs.
Plus, he'll probably give the finger to Mephisto, like DMC Dante, with the dealer knowing he can't handle Naruto.
I Do Not Own Naruto Or Marvel. (Or Devil May Cry.)