Alright, before anyone goes on a rant and says how much of an idiot I am for writing a Twelfth story, I couldn't help but write this as there are rarely stories involving Natsu with Rias and company(there are, but only a few.) The reason I decided to write this is because I am starting to watch Highschool dxd, along with the fanfictions I read about this subject, so I thought I would at least give it a try.

So I am going to make this kind of an AU as I will be adding my own lore into the series, but will try to have canon be included. Not(and I apologize for Issei fans and those who hate repetition), but Natsu will get Draig, because he IS part dragon, so it would only make sense he gets the Sacred Gear. If you guys do have a concept for this story, please tell me wither in the comments or just message me since like I said, I am barely watching the series(as cringy as it is). So this will take place in the end of the Tartaros arc and near the beginning of Highschool dxd, so Natsu could get used to it. So he will have a harem in both his world and DXD, and expect a lot of lemons;) Don't worry, he will have Fairy Tail girls in his harem, but not ALL of them cause that's a pain in my ass. I will make the list at the end of this intro.

And with that said, let's get fired up to an okay story…...maybe

Demons…..Dragons…..these are legends that spread throughout worlds and dimensions. Only two worlds have both myths, and soon…..they will meet through a certain pink haired fool.

'Fiore….Year X791'

"Fire Dragon Iron Fist!" In a simple forest on the outskirts of Crocus, the largest city in all of Fiore, several trees were suddenly knocked down by a powerful force. The person who destroyed them was a male with slightly tan skin, a muscular figure, black eyes and for some reason, pink hair(though he usually calls it Salmon.) His attire consisted of a one-sleeved black coat with gold trimmings, white baggy shorts, black open-toe sandals, and a white scaly-looking scarf wrapped securely around his neck. His left arm was covered by the sleeve while his right one was exposed to the world as it had a red insignia of a fairy. This man is Natsu Dragneel, the Salamander of Fiore's #1 guild, Fairy Tail!

…...Or at least, was a member. "Hmmmm, not bad, but not good enough." Natsu muttered to himself while wiping the sweat off his brow. It has been a full three days since the battle with the dark guild Tartarus was over…..three days since his guild was disbanded…...three days….since Igneel died. The memory was still fresh in his mind, which is understandable to a lot of people who witnessed the death of a parent or parent-figure.

"IGNEEL!" Natsu ran towards a large dragon with red scales, a yellow underbelly and a X-shaped scar on his snort. The red dragon was currently engaged in an aerial battle with a equally large blue and black dragon.

"Natsu, stay back!" Igneel roared as he glared at his opponent, Acnologia. I may not be end his life, but at least I can injure him enough for Natsu to end him! Making a last minute decision, Igneel charged towards Acnologia, who did the same. Time seemed to slow down as both legendary dragons were getting closer…..and closer…...and closer….until….

*RIP*

The sound of flesh tearing apart echoed through the sky. Natsu looked in pure horror at what unfolded. Igneel was able to rip off the dragon of the apocalypse's left arm…...but he did not do this unharmed. Acnologia was much faster…..ripping through half of Igneel's torse. Despite the critical injury, Igneel released Acnologia's arm with a smile as he slowly began to fall. Natsu continued to run towards his father, even as Acnologia was charging a breath attack. "Natsu, in all my life, I never expected to be a father. No matter what, I will always love you…...my son. Follow your heritage and make sure to have many mates…." Igneel closed his eyes peacefully was Acnologia's attack engulfed his body, ending his life.

"NNNNNNOOOOOOO!"

*BOOM*

Natsu slammed his fist onto a nearby boulder, shattering it to bits. No, he couldn't let that memory stop him from living the life Igneel set up for him. Even if his dad was gone, he still had a lot to live for…..like his guild. But what the hell did he mean by many mates? *sigh* even after all the years of being around hot girls, he was still as dense as water. Smh. "I guess I better keep going. Wonder how Happy's doing with Lisanna." Before he left his home to train, Natsu left his little buddy with his first friend since the training was going to be hell and he didn't want Happy to be caught in the middle. Though he was glad Happy was in safe hands, he still regretted not having anyone to talk to. Erza, Lucy, Lisanna, Mira, Juvia, Gramps, Wendy, hell he would even be okay with Gray and Gajeel! Looking at the sky, he noticed it was about late afternoon, which means night was close. "Man, I'm starving." Grabbing his bag, Natsu began to move along his training trip, hoping something would come up.

"Well well, look what we have here?" A voice called out.

"Huh?" Natsu turned his head….only to dodge a black dagger from piercing his head. He looked at his attacker. The speaker was tall, maybe an inch more than Erza, wearing pitch black armor, gauntlets and greaves, though he could see his long blue hair through his dragon-like helmet.

"Who the hell are you?" He demanded with a glare. The man didn't say anything as he lunged towards Natsu, his fist pulled back for a punch. Seeing this, Natsu tiled to the left and slammed his own fist on the attacker's chest….

*DING*

"OWWW!" Natsu did not expect the armor to be as hard as it was. Sure he had punched Ethernano, Gajeel's dragon scales, hell even the Dorma Anim, but this was…..different, as if it was made specifically for him. Seeing his opponent's moment of weakness, the man in the armor grabbed his neck and slammed him onto a nearby tree.

"Hmmm, your reflexes were quick, but your strength is nowhere near the defense of my armor." Giving the man a glare, Natsu's whole body was engulfed in flames, making the mna slightly flinch under his armor.

"Fire Dragon Roar!" The pink haired male unleashed a stream of fire from his mouth, forcing the man to release him. However, the flames struck his right shoulder, though he didn't show his pain. "You wanna make fun of my strength, then try this!" Igniting his feet, Natsu was launched towards the man and began a flurry of punches and kicks. To the dragon slayer's surprise, the attacker was able to intercept each attack with his arms. Shit, this guy's good….I like it. Narrowing his eyes under his helmet, the man caught his fist….as his mouthguard suddenly opened. "What the-?!"

"Draco Lavres!" A purple stream of energy was fired from his mouth, which Natsu BARELY dodged, though it did graze his left shoulder. "Skull Breaker." Clenching his fists, the man's knuckles sprouted out small spikes. He then rushed towards Natsu while swinging his fists, forcing Natsu to jump back. He had never seen anything like what this guy was doing, and it kind of excited him. He always loved fighting strong opponents who had new tricks, even though his friends would scold him for being reckless. "Come on, I know you have more than what you're showing!"

"Fine!" Raising his arms…..Natsu grabbed both the man's wrists, much to his slight shock. Lighting his arms on fire, Natsu gave him a feral grin. "Fire Dragon Wing Attack!" Pushing the arms back, he slammed his flames onto the man's chest, pushing him back a few feet. "And Fire Dragon Brilliant Flame!" He summoned a sizeable ball of fire in his arms before throwing it at the man. Under his helmet, the man smirked before he extended his right hand.

"Dragon Blade: Exciton!" Natsu's eyes widened as his Gauntlets broke a bit….before morphing into a pitch black demonic sword with a jagged blade(if you want a better description on how this happened, think of how Cade Yaeger from Transformers 5 summoned the sword.) Raising his sword, he sliced through the fireball no problem, allowing both sides to crash on to ground. "Not bad, you actually forced me to use Exciton. Only a rare few have forced me to use a Sacred Gear."

"Sacred Gear?" Natsu asked, tiling his head as the man sighed.

"Oh right, this dimension doesn't have Sacred Gears." Okay, now Natsu was really confused, more than he usually was! The way he said that, he sounded like he wasn't even from here. "Hmm, I am in a tight schedule, so we must end this little fight. Otherwise I won't be able to get the other dragonborns."

"Dragonborns…...wait, you mean dragon slayers?!"

"If you refer to those who possess the powers of dragons, then yes." Okay, now Natsu really had a problem with this guy. It was bad enough he was attacked, but now this guy was looking for Gajeel, Wendy and the other dragon slayers.

"Then there's no way I'm letting you win!" Focusing his magic, Natsu's body was covered in lightning-coated fire, making the man's eyes widen.

Two elements?!

"Lightning…..Flame…...Dragon….ROAR!" Opening his mouth, Natsu launched a powerful stream of fire and lightning. Getting over his shock, the man got into a backslash position as his sword began to glow a dark purple aura.

"Exciton: Dark Arts Strike. Liberation!" Slashing his sword, the man launched a large purple energy slash, which began to collide with Natsu's attack. Both combatants roared as they attempted to overpower the other. The ground shook as the two attacks continued to fight for dominance until….

*BOOM*

The attacks were so powerful, they caused a large explosion to occur in the forest, creating a large smoke cloud to rise. Natsu and the man were sent flying back, their clothing and armor began to tear apart. The animals and plants that were around the two were also sent flying back. As the smoke cleared up, Natsu and the man slowly stood up. Natsu's clothes were completely ripped, showing his abs and pecs while parts of the man's armor was slightly cracks, though there was a small amount of blood to run down his mouth. "Shit…..that…..was…...crazy…." Natsu said between breathes.

"Yes…...you…..were….impressive." The man admitted, using his sword Exciton as support. His magic was already a bit low, but with the fight, the man was almost completely drained. I must return to the others.

"Hey….where….do….you….think…..you're….going?" Natsu noticed the man turn his back on the fight before extending his arm. Then, a strange purple magic circle appeared before him.

"The battle was intriguing, but I must return to my colleagues. Until we meet again, dragon of lightning and fire."

"No you don't asshole!" Getting off his ass, Natsu rushed towards the man with a flame coated fist. Seeing this coming, the man raised his sword to intercept the attack, causing a small shockwave to appear. Unfortunately, the magic circle was affected by the attack, much to the man's annoyance.

"Fine idiot, if you wish to join me, then you shall!" Raising his left hand, he summoned another portal behind Natsu. Using his sword, he pushed Natsu back just a few inches from the portal. "You shall never see your world again, dragon." With that, he kicked Natsu on the chest, sending him into the portal.

"NNNNOOOO!" All Natsu could do is scream as he entered the portal before it disappeared. Sighing in exhaustion, the man turned towards his own portal before entering it. That was the last time Natsu Dragneel was ever in Earthland.

'Unknown location'

Emptiness. That's all Natsu COULD see as he was traveling through the portal. He didn't know where he was going, and that worried him. That fight with that guy really did a number on him. Damn, all that work, all that training, and for what, to get my ass kicked again. Natsu thought regrettable while clenching his fist. I'm so weak, how can I see my friends again and get S-Class if I can't even beat one guy with a sword?

Do you want the power? Natsu's eyes widened as he heard a disembodied voice speak to him.

"W-who's there?"

I can give you that power. All I ask is that you let me into your body.

"Huh?!" Who the hell was talking to him? Probably a pervert like Gray.

'Earthland, high mountains'

"ACHOO!" Gray Fullbuster sneezed while trying to focus his new Devil Slayer magic.

"Darling, is there something wrong?" Juvia asked curiously as he was used to the cold, so it would be rare to see him get sick.

"I don't know, but I feel like someone's talking about me."

'Back with Natsu'

I can sense you have a lot of potential and not enough time. If you and I join together, then we can beat anyone.

"Anyone?" Natsu began to imagine standing over all those who mocked him: Gray, Gajeel, Mira, Laxus, Erza, hell he could even beat Gildarts! "Alright voice in my head, let's do it!"

The name is Ddraig, and I will only appear when you truly need it.

"What?! Then what was all that talk abo-aahhhh." Natsu felt his body begin to glow a red aura, giving him power he didn't expect to gain.

We will meet again….partner. BOOST!

*THUD*

"*GASP*." Natsu shot up from the sudden shout in his head. It sounded so much like Igneel or even Acnologia's roar. What the hell was that about? He thought while wiping some sweat off his brow. He finally looked up and noticed he wasn't in the forest or even the portal from before. The dragon slayer was currently in a very elegant bedroom: the bed was queen sized with a red bed sheet, white dressers, a strange screen across the room, and a large window on the side."What the hell is this place, and where am I?" Natsu flinched as he touched his chest, which was covered in several bandages. It must've been from the fight with that knight or whatever. He also noticed his clothes, with the exception of his pants, were folded next to him on a nightstand. I better get out of here before- The sound of the door opening caught his attention. Natsu looked at the door and saw something he did not expect.

"Oh, you're awake." A soft voice called out. The speaker was female with pale skin, long beautiful crimson hair that reached her thighs with a single strand sticking out from the top and blue-green eyes. Her attire consisted of a white long-sleeved button-down shirt with a black ribbon on her shirt collar worn under a black shoulder cape and a matching button-down corset, a magenta skirt with white accents, and brown dress shoes over white crew-length socks(basically what she wears at school, sorry for the lack of creativityXD.) The female was also carrying a silver tray with some fruit and bottles. Now Natsu is known to be a dense moron, as we all know, but even he had to admit this woman was attractive. She smiled before walking up to Natsu and sitting on the bed, placing the tray next to her.

"Ummm, who are you?" The woman gave a slight pout, catching Natsu off guard a little.

"You know it's rude to ask for someone's name without telling them yours." The dragon slayer rubbed the back of his neck sheepishly. He remembered Makarov taught him to act respectful when someone does something for you.

"Sorry about that, I'm Natsu. Natsu Dragneel."

"Well it's nice to meet you Natsu. My name is Rias Gremory, heiress of the Gremory house." The newly named 'Rias' said while sticking out her hand, which Natsu shook.

"So Rias…...where are we?" Rias looked a bit reluctant to say, but she had to make something up for now.

"We're currently at the Gremory house, and this is my bedroom." She took a spoon from the tray before opening a purple bottle, pouring a spoonful of the substance. "Here, take this." She noticed Natsu's nose scrunch up. "It's some medicine that will heal you faster."

"Alright." Opening his mouth, Natsu swallowed the liquid in one gulp. The taste wasn't the best, no medicine is really, but if what Rias said was true, then he would have to suck it up. "Thanks." Smiling at his thanks, she handed him an apple to replenish his strength.

"Natsu, can I ask what happened to you?" Munching on the apple before swallowing it, Natsu thought back to his fight.

"Before I do, can you tell me how I got here?" Rias' mind went back to what happened a few hours prior to Natsu's awakening.

Flashback, 2 hours ago

Rias was currently walking past the gates to Kuou Academy, one of the few schools that had 90% of females and 10% of males. It wasn't a very eventful day: simple school work, club meetings, ignoring the lustful looks from the males. But she still had some things on her mind, most notably the wedding she was forced to attend. Sometimes she hated being a Gremory as she had to do things that benefited her family, but was very uncomfortable for her. A sigh escaped her lips as she moved a strand of red hair behind her ear. "Someone please give me something do to to get my mind off this wedding." She said to whoever(cause if she said the G.O.D word, it'd be like listening to a Justin Bieber soundtrack.) Just as she was going to turn left….

*Boom*

A purple magic circle appeared a few feet from her, much to her shock. Yeah she had seen many people use Transportation Circles, hell she can even make them, but this one felt…...strange. Before she could react, a body was suddenly flung from the portal and landed on the ground before the circle disappeared. Rias' eyes widened as the figure that was none other than Natsu, who was more than battered up. She quickly ran to the male and kneeled down to see his condition fully. He was bleeding from a few parts of his body, his clothes were torn and he was barely breathing. "What happened to you?" She put her ear on his chest, barely hearing his heartbeat. It was strange, first that ortal came out and then this pink haired boy arrived. For some reason, she could sense something…..special about him. "I can't really leave you here. Hopefully Sirzechs will be fine with you." Extending her hand, she summoned a crimson portal just a few inches from the pair. She wrapped his arm around her neck before walking towards the portal, teleporting away.

Flashback end

"After that, I got the family doctor to come and treat your wounds. Luckily, they weren't life threatening, but you were going to have to take it easy from now on." Natsu tapped his chin while humming. It was weird how the portal just brought him to Rias, but he was grateful she helped him out.

"Well, thanks for helping me out Rias!" Natsu said with a toothy grin.

Hmmm, he's pretty cute. Maybe…...maybe he can help me. Rias thought with a smile before a thought came up. "Natsu, I think it would be wise for you to meet my brother so he could help you out."

"Really, think he can help?"

"Mhm, he's one of the smartest people I know, so he will know about that portal." Nodding in agreement, Natsu stood up from the bed before putting on his scarf and sandals and followed Rias out the room. Little does he know, he's about to get the most shocking news of his life.

'Unknown location'

"Kondal, report." A deep voice said from the shadows as the knight Natsu had faced was standing in the middle of a spotlight. The room itself was concealed in shadows, with the exception of a few candles lit around.

"Sir, I had successfully entered the world told in legends and even found one of the Dragonborns." Kondal said before he lowered his head slightly. "Unfortunately, due to the amount of energy I had to use to enter that world, I was unable to capture one of them."

"You wouldn't have returned unless you have some kind of news." A feminine voice called out from behind Kondal.

"Correct Lucina, I was able to transport the Dragonborn to our world, though his location is unclear as I had not chosen a location, rather than here." Some of those in the shadows began to mutter to themselves about the news.

"Though you had not completed your mission, you had at least accomplished something Kondal. It will be your responsibility to find him." Kondal nodded before summoning Exciton and raising it high. "We fight to prevent the dragons from ruling our world."

"We defend the weak from demon kind…"

"And we fight with honor, regardless of our own objectives."

"No innocent blood shall be spilled, even if we must die."

"We…..and the Dragon Knights."

Wow, this was a pretty lame intro in my opinion, lol. True be told, I am BARELY watching Highschool dxd and may use other stories to help me write these chapters. Now I will be following the canon of dxd, though obviously I will make crucial changes, such as introducing Raynare later on instead of her killing Natsu. Also, as you can probably tell, I have made an original group of villains for the story as I don't just want someone like Zeref to just transport Natsu to this universe(in respect to Kript, check out his story Fairy x Devil.)

So as I had stated in the beginning, Issei will not exist in this story(again, I'm sorry) and Natsu will have Ddraig, along with a few new powers from these 'Dragon Knights.' He will be strong, POSSIBLY enough to kill an actual dragon, we will see. I can't promise this story will be updated fast, I can only promise it won't die. So for the sack of the harem, here's who is in:

Rias

Akeno

Asia(maybe I will take her out if enough people say it)

Koneko(she and Natsu won't do it because she and Asia are young)

Xenovia

Raynare

Kuroka

Erza

Mira

Lisanna

Lucy(maybe)

It may grow, it may not, we'll see how this chapter goes. If you have an idea for this plot, please let me know and I will apreciate it.

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Next time: I'M WHERE?!