Note:
Don't know everything about dxd or naruto so have made a couple educated guesses, this includes timeline as well which can be a pain in the ass to find anything on (any help is appreciated). Sasuke arrives in kuoh and well naruto, you'll have to wait for that ;)
Thinking
Kurma talking
"Normal talking"
o0O Hidden Leaf O0o
The air, corrupted by the vile stench of burning flesh was accompanied with the orchestra of hell itself, the helpless masses who screamed in agony as the black flames darker than those of amaterasu burned down to their very bone. Though flames wouldn't be the right words to describe the seemingly endless sea of burning black 'liquid' flooded every street of konoha. Many tried to use various water jutsu but it was pointless as even was water caught aflame upon contact with the mysterious substance. The sky was dyed red
What lied before him could be called nothing other than pure, despair.
"You scared boy" a crocky, familiar voice spoke from within the lone figure who stood atop the stone faces of previous kage bearing witness to the atrocities that lay before him.
"W-who wouldn't be in this situation… I mean..." words stuttered and cloaked with fear couldn't even be finished before the young man dropped to his knees as he watch everything he worked so hard to protect get burned to dust, and then some. It was as if the sky had opened up releasing hells oceans upon the shinobi world flowing with a unrelenting furiosity consuming everything in its path. The destruction could all be traced back to one point in the sky where a large hole in the acted as if it were a faucet, letting what could only be described as the blood of the devil himself pour onto the ground below.
"Naruto! We need to do something" yelled a black haired shinobi with the same fear and horror in his voice. He was the same age as naruto dressed in his signature black cloak atop of a chainmail bodysuit that was covered by a simple gray shirt. But naruto was so engrossed in the sight that lay before him that he didn't hear his approach let alone his voice. "NARUTO!"
"Huh?" the raised voice of a fellow soldier in arms broke him out of his trans. "S-sorry Sasuke.. I don't think there is anything we can do about that". his focus was entirely on the rising level of the black substance which had now risen above most roofs the buildings pulling them completely into its embrace.
"I think I may have a idea to get both you and sasuke out but you will have to trust me on this". Once again the voice from within spoke but this time it's tone was reluctant. "Just gather all the nature chakra you can and get ready for my signal"
The prospect of possibly combating this atrocity swifty changed naruto's tone "alight Kurama, I'll leave this all to you" he turned around to the black haired shinobi "sasuke Kurama might have a way to do something about this so just sit tight for a second". The jinjuriki drop to a meditation poses and concentrated on nothing else but gathering as much chakra as he could.
Five minutes passed as naruto and kurama worked on a possible solution, but the black all enveloping substance had started reach above the kage carvings and to the cliff where the two shinobi had taken refuge. "Alright naruto, it's ready". After hearing this naruto instinctively got into his kyuubi form and sasuke who was getting astiny with all the waiting around swifty fortified this state with his susanoo.
"Alight kurama what do we do?" sasuke asked but before he could get a response the armored boots of his susanoo began to melt from the black flame that washed overtop of the cliff. "Better be quick with whatever it is, my susanoo wont last long".
"Hm yes kurama lets see what you have planned" naruto says and in a instant all of the nature energy he aculated vaished instantly
"Alright" kurama yells as he slams his palms together making a rush of energy which slowly in circles the trio. "let's send you two away from here with a old man six paths gave me"
"Wait, send me away!? What do you mean kurama"
"Sorry naruto, the old man said something like this would happen and this is the only way"
"You don't mean.." sasuke was interrupted by a large light that seemed to muffle all sound and other lights from kurama as he started finishing his jutsu.
"Well, it was nice know you naruto, you too sasuke".
"KURAMA!" naruto yelled as he finally grasped the situation but was enveloped by a blinding light that seemed to numb all his senses.
o0O Kuho O0o
"Ara ara, what do we have here? Someone sleeping in my shrine?" Akeno wondered as she leaned over top of the black haired man who seemed to be fast asleep on the floor. It almost seemed if he was dead by the fact that his breathing was very faint, but for someone like akeno such a detail didn't go unnoticed. "Seems like your almost dead, but you still cling to life even".
you know akeno mused while taking a closer look at the boy on the ground he doesn't look half bad, it would be a shame if such a person were to die, and I can sense some power from him. I wonder if Rias could do something about this, wouldn't hurt to find out
o0O Occult Research Club Room O0o
"Hmm I see, he doesn't appear to be dead but he also doesn't seem to be alive either"
"Well that's why I bought him to you, Rias"
"he does seem to have some power within him. A scared gear maybe? But I won't have enough pieces for both him and issei".
"Alright Rias" Akeno responded "Maybe sona has enough?"
"Doubt it"
"Thats a shame"
"Well he's not dead yet, maybe-" Her sentence when she looked down at the young man who was laid down across a couch and saw him looking back at her. His blood red eyes and black orb with tails looked right into her eyes with such intensity that it was almost as if she was within a trans. "Ooh my! You scared me".
"Ara ara you're awake, and here I thought you were almost dead"
"Where am I?" sasuke said with worried tone as he scanned around the room with his sharingan. There were two people with him. the first had a head of crimson hair which flowed down past her waist, with two long strands framing both sides of her pale, peachy face accompanied by two deep blue orbs. The girl who seemed to be around the same age as sasuke had a bust size that rivaled that of the slug queen that was kept in bay by a thin layer of white cloth with black stripes. Letting his eyes drift further down this woman's frame sasuke came across a set of very luscious thighs but with his trained eyes he could tell they were quite muscular.
His attention then changed to the second person in the room who seemed to be standing at attention behind the first women. Her dark ebony hair was tied up in a high ponytail by a yellow ribbon, though two sideburns seemed to escape and fell down both sides of her seductive face, that bore a smile that seemed to be a permanent occupant of her face. Her engrossing dark purple eyes where overshadowed only by the even larger bust size than the previous women, which seemed to be covered by the same strange clothing.
"You were found passed out in akeno's shrine"
"Whos akeno?"
"Ara ara thats me" The ebony haired women spoke as she stood forward into what she imagined would be sasuke's view, but with his visual prowess he had already seen her.
"I see.."
"You certainly have a interesting eyes, are they your sacred gear?"
"Sacred gear? What's that?"
Hmm Rias mused maybe he isn't aware of the sacred gear inside his body, or it has just awakened. That would explain him being unconscious at akeno's shrine, but i've never heard of a ocular sacred gear.
"Well" akeno was the first to speak after Sasuke's question "A sacred gear is a power bestowed by god to humans"
"God" he said with a raised eyebrow
"Well, do if we a devils" rias said before letting out her wings with akeno letting hers out swiftly after. "Then there must be a god".
I see, this is quite the discovery sasuke thought as he looked at the two devils with his sharingan. They have power that's for sure even if it's quite weak, wait where's naruto? "You didn't perhaps see another person when you found me?"
"No" akeno answered "It was just you although your clothes were torn to shreds so I had them changed. Although the only male clothes available was a school uniform, I hope you don't mind".
"You changed my clothes" Sasuke asked as he looked down at the clothes he was wearing, he was wearing the same styled shirt as the other two women however there was some other differences. He had overtop of the shirt was a grey jacket accompanied by grey pants.
"Ara ara, did you want me to?"
"Huh?" sasuke responded with a deadpan expression.
"Ohh you're no fun. But to answer your question I didn't, I had kiba do that".
"Alright" he said not interested in the slightest at the playful jabs akeno was throwing at him "well I appreciate you taking the time to make sure i'm alright but I wouldn't want to impose any longer".
"Ooh think nothing of it, I mean you do know our secrets so we can't just let you leave that easily" Rias said as she retracted her wings
"Is that a threat!?" the air in the room suddenly got extremely thick as sasuke unconsciously let out a menacing aura and stared right into Rias's eyes with such intensity that she felt she was naked before him.
She gulped before raising her shaky voice. "W-well so long as you.. don't tell anyone we should be fine" she then turned to her queen "right akeno, it should be fine right".
The mentioning of her name broke akeno out of a trans as she was being suffocated by the aura sasuke exserted. "Yes of course R-rias"
"Hmm, if you say so". Sasuke said with a slight smile as he found out he didn't lose any of the prowess he possessed back in the world of shinobi.
o0O 2 week later O0o
Sasuke since his arrival in this new world seemed to have made a pretty decent life for himself. Given his set of skills he, albeit reluctantly decided to put those skills to use to get the necessary funds for his new life. He was still searching for clues on naruto location but with no real leads he decided it would be better to use his time to set up himself up. This lands currency was different to his homelands but at the same time quite similar, He was able to obtain the necessary shelter, clothes and food for one to stay alive and didn't live in luxury even if he had the funds to do so. Now with a base of operations set up he decided it would be best to start searching for naruto, and with no contacts he wound up in the place he started in. Kuoh Academy.
Now being much more acclimated with the local environment and spiritual energy he was able to safely gather and suppress his powers. As he was making his way through the campus he suppressed his powers to a point where no one would be able to see or sense him. Though of course there is always exceptions but no one he had seen so far seems to have such an ability. Making his way into the occult research club that he had awoken in he could sense 23 people in what he assumed was the main room.
Are they having a party or something he mused as he walked up the stairs to the second floor. Well no matter I'll just introduce myself to them as well.
Opening the door he witnessed a little girl slam a male into the roof with only a wooden pole, well in his eyes it was weak enough to be a messily wooden pole. Still keeping his presence hidden he was surprised when a women dressed in a maids outfit looked him in the eye before giving a slight, but noticeable bow. Well this is most certainly an interesting development. The maid, the only one in the room to notice him had a head of gray hair that was tied into four separate plats, two shorter and falling in front of her, and two longer taking up residence behind her back. Her eyes, the same color as her hair had a calm yet warm feeling to them while further down her face was the only makeup needed for a beauty of her caliber in the form of red lipstick. Her maid outfit consisted of only two colors, blue and white that concealed most of her form with only one exception, her abnormally large bust, which seemed to be normal in this world.
Decided he had stared at the maid long enough he decided to make his presence known. "Well seems like we are having fun in here" he said with a light chuckle. Everyone in the room, excluding the maid, turned around with shocked expressions as they didn't think anyone could sneak up on them considering their powers.
"Wa.. s-sasuke when did you get here?" Rias question with a few nodding in agreement,
"Just a second ago, I was hoping to talk to you about something but if you are in the middle of something I'll wait".
"Who the hell are you!?" The voice came from a man who, for all extensive purposes, looked like a playboy. He wore a head of blood hair and was dressed in a red jacket and white shirt. Most noticeably though was the fact he was surrounded by 15 surprisingly attractive girls which only seemed to reinforce sasuke's previous assessment of him being a playboy.
"Hmm, who are you?"
"Mira teach this boy some manners".
Without any reply the little girl that had just knocked out that boy with the strange gauntlet rushed towards sasuke with her wooden stick. With a less than enthusiastic but powerful, for her at least, she swung her stick at the uchiha who simply took one step to the side to avoid it.
Now angered that someone dodged her attack she went to attack again, this time putting in some real effort but was stop by the maid who simply had to raise her voice slightly.
"You can settle any grievances in the rating game, so please refrain from lashing out inside the building". Her voice was calm and yet it had some lingering strength behind it.
"Mira back" the playboy order and mira swiftly complied. "So can I assume then that you are a part of my fiance's peerage?"
"No he's not simply a… acquaintance". Rias spoke finally wrapping her head around the transpiring situation.
"Then why did you say settle this in the rating game Grayfia?" The playboy asked.
"I simply wished to de-escalate the situation and that seemed like the best way to do it". She said with a slight simile as she tried to see the limits of the man before her who was named sasuke.
"Ehh well on matter, I don't want to breathe this putrid air anymore" as he said this a magic circle materiales teleporting the the playboy and his harem back to the underworld.
"So now that the nuisance is out of the way, do you think you would be able to answer a couple of my questions Rias?"
"Huh?" rias replied seemingly confused at the total lack of interest sasuke was showing about the evenings events. "Y-yes of course".
"Well that's good, but may I know your name?" sasuke asked while turning to the maid who was the first person powerful enough to notice him when he was actively supervising his presence.
"Lucifuge, grayfia lucifuge".
"Uchiha, Sasuke Uchiha. Pleasure to meet you grayfia".
"No the pleasure is all mine, it's been sometime since i've seen someone as strong you, even though you are human".
"I agreed, it has been sometime since i've met someone of your caliber".
"You flatter me"
"As do you"
Sasuke's eyes then drifted to the unconscious boy on the ground. "Is he going to be okay?"
"U-uh yes, yes he should be fine". Rias said as she rushed to issei's side making sure her statement was in fact true.
He then turned his attention back to the maid. "One question for miss grayfia first".
"Just grayfia is fine" she responded.
"Alright then, grayfia you mentioned before something called a rating game. Care to explain to someone who is uninitiated in such terms". He questioned making sure to read all her movements to ensure he was given the truth.
"It is in simple terms, a fight between two devils and their peerages". She answered.
"Alright then, care to explain what a peerage is". He further questioned but before he received an answer someone else spoke up.
"Isn't it your turn to answer one of our questions". The one who spoke up pointed a single sword towards sasuke, intending to showcase his dominance over the human, though this didn't startle sasuke in the slightest. The figure behind the sword was nothing more than a amature but held himself in a manner of great arrogance, something sasuke couldn't help a giggle at. "What's so funny!" The figure said with a tone of annoyance.
"Nothing you could comprehend". Sasuke said inwardly smiling at the boy in front of him.
"Why you, don't look down on me!" he yelled before charging towards the shinobi.
"KIBA!" The commanding tone seemed to bring kiba back under control as he back up towards the rest of his group.
"My apologies Rias".
"Well anyways sasuke" rias back to her normal composed self. "To answer your question a peerage is like a set of subordinates a devil can acquire through certain pieces".
The answer was vague but gave sasuke a good enough idea of the term peerage, and he couldn't say he was very happy with the idea of it. "Well to me it sounds like a horrible system".
"Well its most certainly not perfect" grayfia interjected. "But it's the best system we have at the moment, and considering our loses in the previous war something like this must happen if we devils are to keep the facade of strength to the other factions".
"Grayfia why are you saying so much to this outsider, for all we know he could be-" rias questioned but was interrupted by grayfia.
"He would get answers even if we didn't want to give them" she said while giving sasuke a cold hard stare as she still struggled to comprehend the limits of his power. "Isn't that right sasuke".
"Well i'll be damned, if I didn't know any better i'd say you had eyes like mine".
"Not eyes, simply experience".
"Makes sense".
"Well as fun as it would be to continue this conversation, I must be getting back and making sure your bother Sirzechs is not slacking". She gave a slight nod before disappearing through a magic circle much.
"Akeno can you take issei to the infirmary, and take everyone else with you I need to speak with sasuke now".
"Rias with all due-" kiba spoke up but akeno interrupted.
"Of course Rias" she then turned to the others and motioned for them to follow. "I'll come see you when your done".
"But.."
"Kiba! Lets go" akeno said with more authority in her tone.
"Of course". The four members of rias peerage walked out of the room all expect issei who was being carried out by rias's queen.
"Well then sasuke, what is it that you wanted to ask".
"You didn't have to send them out, it's not that important"
"It was my decision"
Sasuke finally walking out of the door way took a set on the couch that he had woke up on just 2 weeks prior, with rias taking a set on the chair opposite him.
"Well I wanted to ask if you have seen any" he stopped to try and structure his next words carefully not wanting to give anything away. "Unusual activity".
"Ahh, don't even get me started on all the things that have been happening if your talking about the one you mentioned when you woke up, no we haven't heard anything on him, or her you haven't been really descriptive with this person".
"Yeah that ture, do you have anyway to locate a missing person".
Rias eyes lit up at his words If I play this right I may just get out of marrying riser, she mused. "Well, my brother might be able to but" she took a long pause hoping to lure the shinobi in.
"But what?"
Almost, he's perceptive so just take it slow and don't make him mad. "Well, I can't just ask my brother to help a human".
"Hmm that's true" he thought aloud.
Bingo. "You know what, if you can do something for me I'll do whatever I can to help you in finding this person". She said struggling to hold back a smile as she thought she had cornered him.
"Hmm, an interesting proposal. can I assume you want my help in this rating game of yours".
Dam he's sharp, no matter I almost have him. "Yes you see, riser is my fiancé and this rating game is the only way for me to get out of that engagement. You see-"
"Say no more" sasuke said as he got up. "Just give me the dates and a report detailing all of your peerages abilities and any known abilities of the enemy and I'll do the rest".
"Uh isn't that a lot to ask for-?" she was going to ask him but somehow he just vanished right before her eyes. "Well at least we know he is fast. Hey how am I even going to find him".
edit: got rid of all bushido naming so stop complaining ;) Though im not perfect so if I missed some my bad.