A/N: What's this another DXD story. Now let's just get some things out of the way. Excalibur? Yes. Naruto here will be wielding an Excalibur. Not a fragment but instead the Fate Excalibur wielded by Artoria Pendragon. How he comes to wield that will be explained later. Underworld? As you see in the summary, Naruto will become Rias' adopted brother. He will be a devil but as far as he's concerned the devils can bite him. Issei, perverted Idiot who's gonna get clocked in the head a lot. Fate characters? Expect a few others. Rias? Nothing more than a sister and her peerage will have nothing to do with him. Now let's get into this story.

Disclaimer: I own nothing but the plot line of this story and any I write.

(Start)

On a destroyed battlefield, corpses laid. Many with weapons sticking out of their bodies. Some with spears, some with swords, some riddled with arrows, others were beheaded. In the center of it stood two knights. One clad in silver and red armor with a horned helmet. The other, a pitch black armor with a spiked helm with yellow covers over the eyes. A black and red waist cape was located on the black knight as well. In their hands sat both of their weapons. The silver knight had a large silver and red blade in their hand while the black knight had a black and red sword in theirs.

They rushed each other, their armor clanking due to their movements. The slim dark blade clashed against it's rival. The sound of grinding metal blasted their ears as both tried to forcefully over power the other. They eventually pulled away before rushing again. Their swords clashed again and again. Sparks flying until the silver knight eventually got the upper hand. The side of it's sword clipped the black knight's helm, dazing the black knight. The black knight staggered away before it turned to it's opponent and was forced to the ground due to a shoulder barge from their opponent. The silver knight stood above the other with their sword raised above their head. Before anything else could happen a loud alarm blared out across the battlefield.

"YOU'VE GOT TO BE FUCKING WITH ME! I HAD THAT IN THE BAG!" The silver knight cursed in a female voice. A low chuckle could be heard from her opponent.

"I'll admit. I was saved by the bell." The black knight said as the area around them faded away revealing that they were in a field of flowers.

"Your damn right you were!" The silver knight snarled as she stomped her foot on the ground.

The black knight's armor faded away revealing a young teen of seventeen years old with bright blonde hair that seemed to pale at the tips. Bright blue eyes that showed his happiness at his partners anger. He was wearing a orange tank top under a black jacket and grey jeans with black nike shoes. Looking over at the silver knight, he saw he punching the ground in frustration as her armor disappeared in a bright red light. Long golden hair tied into a pony tail and bright green eyes were the things that first caught his attention when they met. A red jacket left unzipped revealing a white and blue tank top and booty shorts with a pair of brown boots. Walking over to her, the male offered his hand to the woman took it without a seconds hesitation. A brief memory flashing within her mind.

(Flashback)

She was chained to a wall. A needle dug into her arm as she heard the muffled words of other people. Her thoughts remained on escaping and getting revenge against the guys who dared to experiment on her. The pain from the drugs that had been constantly forced into her body forced her to black out though. After darkness consumed her, she was quickly awoken by the blaring of an alarm. Not only that, but she found herself on the ground, her blade laid on the ground in front of her. After her vision came back to her, she looked upwards only to stare into the blue eyes of her savior. His pitch black sword that swallowed light with blood red markings in his off hand. He offered her his hand and a small smile came to the girls face as her savior helped her out of her current prison.

(Flashback end)

"Mordred!" The black knight called as the silver knight, Mordred was forcefully snapped out of her thoughts.

"What's up Naruto?" She asked as the other blonde shook his head.

"I asked if you'd be fine looking after Millicas today." Naruto said as Mordred nodded her head.

"Of course. The little brat and I will be fine." She said as she clasped her hands behind her head. "The Question is...are you ready?" She asked as Naruto nodded.

"That spar helped me work out any form of anger I might have before coming face to face with Riser." Naruto said as Mordred smiled and patted him on the back.

"It seemed to have done wonders for you as well." Naruto said calmly as Mordred laughed.

"Not gonna lie. I've been feeling a bit on the off side lately. So working out some steam like this was just perfect." She said before she remembered something important. "Thanks for that by the way." She said quietly, gaining Naruto's attention.

"There's nothing to thank me for. I wanted the both of us at our strongest and besides. I thought I'd give you an advantage by letting you fight somewhere you familiar with. The battle of Camlann just happened to be the first thing that came to mind." He stated calmly as a large black circle appeared below them.

The two were then enveloped by a dark red almost black light before they found themselves outside a large mansion. The two entered the mansion with a smile on their faces.

"So you sure that your alright with looking after Millicas?" Naruto asked as he and Mordred stopped outside their rooms.

"Yeah don't worry about it. You go do your thing and Millicas and I will be waiting for Uncle Naruto to return." She said teasingly as a smile appeared on Naruto's face.

"Alright then. I'll see ya afterwards." He said before he entered his room. Shutting the door behind him. Mordred stayed where she was for a bit longer, her eyes lingering on the door before she entered her own room.

(With Naruto)

The two toned blonde was currently sitting on his bed, his thoughts occupying his current family. A caring mother, a strict elder sister, a overprotective big brother, an otaku for a sister and his dimwit of a father. Don't get him wrong, he loved his family with every fiber of his being but his father didn't have the smartest ideas sometimes.

(Flashback)

"Why did she react the way she did?" Zeoticus Gremory, Naruto's adoptive father, said with a groan as he remembered his daughters reaction.

"We've basically sold away her happiness. We're forcing her to marry someone she doesn't want. Of course she would react that way." His wife, Venelana said as she was brushing her hair. "Now, I am going to speak with Lady and Lord Phenex about the engagement. Naruto is in the library doing some studying and I expect you to leave him be for now." She continued, giving her husband a pointed look in the mirror she was using.

"S-sure thing." Zeoticus said, sweating lightly.

After Venelana had finished getting ready for her meeting, she gave her husband a quick peck on the cheek before she vanished. When Zeoticus was sure that she was gone, he ran to the library in a hurry. Already having devised a brilliant plan in his mind.

After entering the library, he quickly looked around before he saw the thirteen year old Naruto sitting at a desk reading up on the history of devils.

"Naruto my boy. How's my new addition to the family?" Zeoticus asked as he quickly walked over to the boy who placed his book down.

"I am doing well father." Naruto said, having already been told by Venelana to freely address them as mother and father.

"Say Naruto, I know your studying and all, but let's say you come with me for a quick sec." Zeoticus said with a goofy grin as Naruto raised a brow before he started connecting the dots.

"Father I believe this to be a very terrible idea." Naruto said quickly before Zeoticus grabbed him by the hand and dragged him out of the library.

"Trust me son. This is gonna be great." He said happily as Naruto shook his head as he was being led to the family room.

'Great for entertainment perhaps.' Naruto thought to himself before he noticed that they had arrived. Looking around, Naruto quickly found a chair for himself to sit in before he noticed Zeoticus calling someone. After taking his seat, he dug his nose into his book and heard as his father was being quickly chewed out.

"Not listen honey. I promise you that it's not Riser your meeting. It's someone you'll come to like very quickly." He assured the person on the over line before it was cut.

Naruto sighed as he watched the giddy smile on his fathers face grew once the doors to the room opened. Glancing at the door, he saw a girl with bright red hair and Bluish green eyes wearing a red dress. She glanced at Naruto who turned his attention back to his book before the girl turned to her father.

"Well what is it?" She asked as Naruto could already see how this would play out.

"Well Rias, your mother and I talked about what we had done to you. Forcing you into the contract with Riser and we felt bad. Now your mother wanted to hold off on you two meeting." Zeoticus said pausing to gauge his only daughters reaction.

'For a very good reason.' Naruto thought to himself.

The young red head was staring at the ground. Her face hidden from view but if one looked carefully, they would notice the shaking of her shoulders.

"Allow me to introduce your younger brother Naruto!" Zeoticus announced as the blonde bowed his head.

"So not only have you signed away my right to marry someone, but you've gone and replaced me as well." Rias said quietly as Naruto stood to his feet and left the room, carefully as to not draw attention to himself.

(Flashback End)

After he left the room, he remembered hearing Rias screaming at their father and the sounds of him panicking when she started firing off some magic spells she knew. It had taken a while for Naruto and her to get onto a tolerable state, but they eventually found themselves enjoying the company of one another. Getting off of his bed, Naruto opened his door to find a grown woman with silver hair dressed in a maid outfit standing in front of his door.

"Hello Grayfia-onee-san." He greeted, getting a smile from the stoic maid.

Grayfia Lucifuge, the current wife of Lucifer and Naruto's sister in law. When Naruto was brought into the family, she was another one who he had to work on developing a better relationship with. Grayfia saw him as another member of the family and served him like a servant would their master. It wasn't until later that she would stop on Naruto's behalf and treat him like a sibling. You could say that while Sirzech's fawned over both of his siblings, he favored Rias a bit more than Naruto. Not that he minded, in fact it's because of that, that Naruto's relationship grew to the point it was at now.

"Are you ready?" She asked as Naruto sighed.

"Don't be surprised if I try to hack off a limb or two." Naruto warned her as he stood next her.

"I'll step in before anything major happens." She said before the two left in a blue magic circle.

(Kuoh Japan. Kuoh Academy ORC Club)

The two appeared within an old worn down building. Looking around, Naruto smiled lightly at the fact the room looked more westernized then he thought it would've. Of course, his actions were currently throwing the occupants of the room on edge.

"And here I thought you would've made this place fit in more with your little habit." He said as he turned to stare eye to eye with a red haired teen who sat behind a large oak desk.

The owner of the red hair was beautiful young woman with white skin, blue eyes with a figure most men saw as their dream women's figure. On her face though was a slight scowl which gave her a fiercer look then usual.

"What's gotten you in a foul mood?" Naruto asked sarcastically as he noticed movement on his right.

Turning to the movement, he was greeted by a sight of someone who annoyed him to no end. Issei Hyoudo. Issei is a high school student of average height with short spiky brown hair, with two short locks of hair behind his head, and light brown eyes. Though what annoys Naruto about this teen was his perversion. While Naruto can admire his desire and will, he also finds the same features about the boy to be annoying. Such as the brat's constant screaming of his dream of becoming the Harem King.

"What the hell are you doing here asshole?" He asked, glaring at Naruto who had to restrain from impaling the fool.

"Issei!" The red head called, getting the boys attention. "Try not to piss off my brother more than you usually do." She warned as the brown haired boy adopted a look of utter terror.

"B-brother?!" He asked in fear as Naruto let out a small smile.

"Allow me to properly introduce myself to your pawn and bishop Rias." Naruto said as he threw a pointed look to the red haired girl. "My name is Naruto Uzumaki. Otherwise called Naruto Gremory, Rias' adopted younger brother." He introduced with a small flick to Issei's forehead before a blond haired girl in a nun's outfit walked up to him.

"It's nice to meet you. My name is Asia Argento." She said as Naruto smiled and pet the girls head.

"Aren't you just precious. Why can't you have more pieces like her Nee-chan?" Naruto asked as Rias gained a twitching.

"I didn't invite you here to listen to you nitpick over the people I bring into my peerage Naruto." Rias said with a very strained voice as Naruto smiled.

You see, Naruto loved to tease his sister by judging those who she reincarnates using her evil pieces. The Evil Pieces were created the current Beelzebub, Ajuka, in order to replenish the number of devils that were lost in an event called the great war. Though, even after being taught about these items, Naruto himself rejected the idea of using the Evil Pieces and never got a set of his own. Stating that he would never use those pieces to reincarnate people into his own followers and would rather earn them for himself.

"She has a point there Naruto. No need for you to worry about the small details." A lovely voice that brought a large blush to the face of the pervert in the room stated as Naruto's eyes trailed off to stare at the person now behind Rias.

"What are you doing here mage of flowers?" Naruto asked as the others turned to see a woman with her face covered by a white hood. A white robe covered her body, yet the robe parted at her shoulders and covered everything down past her biceps. This was not the only place it parted, it parted again around her legs to show that she was wearing black pants with brown boots. Her chest was open to the world, covered by a black shirt that left a respectable amount of her chest open to the world.

"I just thought I would come and see how my investment is doing." The Mage Of Flowers said as she took off her hood, revealing her silver hair and purple eyes before she walked over to the back of the two toned blonde and draped herself over his back. Lightly holding him as her chin rested on his shoulder.

Naruto rolled his eyes at her actions before he turned his attention to his sister, the silver haired mage still holding him him.

"Alright then. How much longer till the jackass shows himself?" Naruto asked before he noticed the temperature of the room increase. "Speak of the devil and he shall appear." Naruto muttered under his breath as he turned around to gaze at a golden magic circle that appeared.

Small wisps of flames spewed forth from the circle as another blonde haired male walked into the room. The man appeared to be in his early twenties with blonde hair about the same length as Naruto's own with eyes a darker blue then Naruto's own. His outfit consists of a burgundy blazer with gold embroidery on the right with matching pants and black dress shoes. Underneath his open blazer is a white dress shirt that is not fully buttoned, giving a slight view to his chest.

"It's been a while since I have stepped foot into the human world." A voice seeped in arrogance stated as Naruto had to resist the urge to growl. A large broadsword made completely of black and red energy roared to life in his hands before a quick swing snuffed out the life of the flames.

"We don't want you burning this place to the ground Riser. So cool it for once." Naruto growled as his sisters Fiancee walked over to stare eye to eye with him.

Riser however ignored Naruto and turned to Grayfia, giving a bow of respect to the one revered as the strongest female devil. He spoke in a sickly sweet tone.

"It's an honor to have you oversee this meeting Grayfia-sama but please, do try and keep this mutt on a leash." He said, referring to Naruto, whose eyes flashed a sinister gold before they returned to their normal blue.

"It is nice to see you as well Riser-sama. But I think you should resist from making any remarks that would force Naruto-sama's hand." Grayfia warned as her eyes went to her brother who was glaring at the elder blond while the woman draped over his back giggled.

(Timeskip, End Of Meeting.)

Rias plopped down in her seat in frustration, the meeting went over well but she knew that she would have to work harder now to get out of her marriage. It didn't help when Issei tried to attack Riser only to be stopped by a member of his peerage. She turned to see her brother leaning against the wall with his eyes closed, the one he calls Mage Of Flowers sitting next to him on a small cushioned wooden stool.

"I wanted to ask you something Mage Of Flowers." Rias stated getting the silver haired woman's attention.

"What is it Rias-san?" She asked as her investments sister stood from her chair.

"At first glance, with the ten days we were given for training, do you think my peerage could beat Riser." Rias asked, wondering what this person, someone who seems to be closer to her brother, may think.

"At first glance, I would have to say that experience may be the deciding factor of this little fight." She answered, one of her hands, raised to her chin as Naruto pushed off the wall. "Oh it seems that we must be leaving." She said as she stood to her feet and dusted herself off.

"My final question. Who are you?" Rias asked as a black circle appeared around Naruto and her target of interest.

"Naruto calls me Mage Of Flowers. But that's just my title. I'd rather you call me Merlin." The now named Merlin said as she waved goodbye to those within the room as both her and Naruto were teleported out of the room in a dark red flash.

'Merlin?' Rias thought to herself, before writing it off as just a coincidence. 'My brothers sword has that of a holy aura, and he has a mage named Merlin working with him. It has to be a coincidence.' Rias ended her train of thoughts.

Her brother having a holy sword and working with someone named Merlin. If someone came up to her and said her brother was the reincarnation of King Arthur or something, she laugh in their face before walking off. If only she knew of how close to the truth that would be.

(END)

A/n: So yeah, I'm not going into the Riser fight just yet. That will be next chapter, for this I just wanted to introduce Naruto and his little crew. Now for Merlin, I will be using the Fate Prototype Version of Merlin, for those who may not know, Fate Prototype Merlin is a woman, so I thought it would be perfect for this. Naruto's little crew so far is Mordred and Merlin.