Yes, I caved like the weak willed person I am and wrote the start of my single pairing Natsu/Erza story. I know I said I wasn't going to… but if this isn't the first story you've read of mine, you'd know by now, that when I say that, you can almost guarantee that it will become a lie eventually.

I think it was due to how much I tore into Erza in MOTR and even though everything I wrote was true, the fact remains, that Erza was my favourite female character for a long part of Fairy Tail and Natsu/Erza was my first favourite Fairy Tail pairing, so I think my subconscious forced me to write this, to balance out my pro/con Erza writing.

I can't promise frequent updates or anything of the like, but like always, I'll endeavour to give you all my best work and while it may take many years… many years… I will finish each and every story I start.

Without further preamble, enjoy the chapter.
SSJ3 Kyuubi Gohan.

Disclaimer – I don't own anything from the Fairy Tail anime/manga. All I own are my original characters and plot twists.

'Talking'

"Thinking"

*expression*

Flashback

Techniques

Chapter 1 – A Promise

Things were looking bleak, with the revelation that Lucy had been captured. Abyss Break had just been stopped, giving the guild members of Fairy Tail a bit of breathing room, only for the announcement from Jose, of their capture of Lucy, to put a stop to that. The entirety of Fairy Tail started to lose morale and Jose's shades started to overwhelm them. Inside the Phantom Lord Guild, Natsu cradled Erza's downed form, exhausted from defeating Aria.

'Natsu… release your power.' Said Erza tiredly.

Natsu looked to the downed redhead in surprise.

'There is an untapped power… sleeping within you… believe in yourself and awaken it. The time is right. Lucy, the guild, you need to… protect them.' Said Erza weakly.

'Erza… do you really mean that?' Asked Natsu quietly, stopping Erza momentarily.

'Natsu, what do you… mean?' Asked Erza in confusion.

'I know… there is a power… hidden deep within me.' Said Natsu, avoiding her gaze.

Happy looked at Natsu in curiosity, while Erza looked at him in bewilderment.

'Then why… why haven't you released it? The guild needs your strength Natsu!' Exclaimed Erza in bafflement.

'Well, at the beginning, I thought the guild would benefit more from my attitude and cheerfulness. Erza… this power… it's related to my Dragon Slaying Magic… but…it's a much… darker power, unique to me. If I unleash it, I won't be the same again. The Natsu you know, the Natsu who laughed and went on adventures with the others… he might not remain.' Said Natsu seriously, looking at Erza seriously.

'Natsu, the guild is your family… it's our family, we won't turn on you.' Said Erza firmly.

'Erza, promise me… promise that if I unleash this power… that even if the others distance themselves from me… if they scorn me… promise me that you won't… promise me that I'll always have you on my side.' Said Natsu quietly.

'… I promise.' Said Erza, after a moment.

Natsu gently lowered Erza's form back to the ground and stepped away from her.

'Then before I do this… yeah, I'm really sorry about this Erza, but you asked for it, so you'll need to deal with it.' Said Natsu, looking at Erza, with a hint of regret.

'Deal with what?' Asked Erza in confusion.

'Me.' Said Natsu, before kissing Erza, much to her surprise.

Happy gawked at the scene in shock, not knowing what his father figure was doing, while Erza froze up completely, only to feel her right gauntlet burning, causing her to quickly remove it and send it back to her pocket dimension.

Natsu then stood up calmly, ignoring the flabbergasted Happy and stunned Erza.

'I order you… to come out… E.N.D..' Whispered Natsu, before his form was engulfed in a black wave of energy, that quickly expanded and pierced through the mobile guild, shattering the roof above them and the ground below them.

-line break-

A man with long flowing hair was sitting peacefully on a throne, right arm resting on an arm rest, while his left held a book. Without knowing who this person was, one would assume they were a scholar, or an academic of some kind, sitting down to read and expand his mind. However, as the book he held started to glow, the man looked at in surprise, which only intensified, when the book dissipated into black particles of magic, before rushing away from the man, being pulled towards another source.

'I-Impossible, has Master E.N.D. actually been resurrected?' Stammered the man, in shock at this recent turn of events.

-line break-

When the black energy surrounding Natsu had faded away, his new form was revealed. The parts of his left arm and leg, that were visible through his clothing, had become covered in dark red scales. His left hand and foot had also morphed into claws, with black nails. On the right side of his body however, were numerous dark markings. It looked as though the shadows themselves were crawling along his body. However, amongst all the black, was a bone white symbol, emblazoned on Natsu's right pectoral, a skull of a dragon. It featured many vicious look spikes and two long horns, which spiralled outwards, before bending about halfway through and pointing inwards slightly. Surprisingly though, similar horns to those depicted on the tattoo, now sprouted out of Natsu's head. The horns were a solid black and clashed heavily with Natsu's salmon coloured hair, which had grown shaggier.

Natsu took a deep breath, before two wings burst from his back. His left wing was easily a scaled down version of a dragons. Red with thick spines and fleshy, cream coloured, membranous-like material, between the spines. The right wing though, looked much more odd. The spines were white and in between was the same black as his horns. The wing itself was also shaped differently, not extending out as the dragon-like wing did, instead, pointing up and only flaring out a little.

Natsu turned to face Erza for a moment, causing the powerful knight to freeze, as she felt the immense power rolling off Natsu. Natsu's left eye had also changed, now having turned yellow, with a black pupil in the centre.

"So dark…" Thought Erza in shock, never expecting the hidden power within Natsu, to be so malevolent in nature.

'I'll be back in a minute, Happy, stay with Erza.' Ordered Natsu, his tone having become slightly colder than normal, but still unmistakably his.

'A-Aye sir!' Affirmed Happy nervously.

Natsu nodded and closed his eyes for a moment, before his wings flexed and he crouched down. In the next moment, Natsu had rocketed through the roof, appearing in front of Gajeel, his back to Lucy.

"W-who's that?" Thought Lucy nervously.

'Who the hell are you… *sniff* Salamander? What the hell happened to you? Gihihihi, doesn't matter I suppose, since now you and I can have a real fight.' Said Gajeel, looking at the creature in front of him fearlessly.

'You should assume the full form of your dragon, otherwise, I can't guarantee you will live to survive today.' Said Natsu calmly.

'Bold words. What makes you think you can force me that far?' Asked Gajeel.

Natsu glared at Gajeel, before clenching his left fist and punched the air in front of him, launching a fist shaped blast of fire at Gajeel. Gajeel shifted his head to the side, letting the attack pass him, only for it to demolish the wall behind him, causing the few Phantom Lord Guild members still there, to run away in fear.

'So that's how it is huh? You really want to see which one of us lasts the longest.' Smirked Gajeel.

'No. I can hold this form indefinitely. I'm sure you know what that means, don't you?' Retorted Natsu.

'Really? With blondie back there?' Asked Gajeel, confusing Lucy.

'No.' Said Natsu simply.

'So red then?' Queried Gajeel, getting a nod from Natsu.

'Interesting.' Said Gajeel, before walking over to a portion of the destroyed guild wall and grabbed a bunch of iron nails.

'You know, this has a fifty-fifty chance of working for me.' Commented Gajeel.

'Then for your sake, hope luck is on your side today.' Said Natsu calmly.

Gajeel smirked, before eating the nails and willed his body to change.

"Come on!" Thought Gajeel furiously, before feeling his body glow in a silvery sheen.

'Today's your lucky day after all it seems, you'll live.' Said Natsu, as his opponent transformed.

Gajeel body was now covered in silver scales. His head was almost square in shape and his lower jaw had the appearance of being hinged. His eyes were beady and circular, with no pupils and black sclera. Around his eyes were small black markings, which continued around to the back of Gajeel's neck.

'Now, let's fight. There is only room for one dragon in the sky after all.' Said Gajeel.

'Fortunately for you, I'm not only a dragon.' Said Natsu calmly, before appearing in front of Gajeel in a flash, causing the Dragon Slayer's eyes to widen.

'I'm also: a demon.' Said Natsu, before his right hand had grabbed Gajeel's head and slammed it into the ground, sending them through the floor and down to the lower levels.

"So… am I just supposed to hang here?" Thought Lucy gloomily, as the two dragon's fought for dominance.

-line break-

'Erza, Happy, what are you two doing here?' Asked Gray, as he approached the downed knight, who had managed to sit up, with Elfman and Mira in tow.

'Don't tell me you fought someone in this state?' Asked Elfman in shock.

'The one who defeated Aria… that was you?' Asked Mira in surprise.

'I didn't want you all to see me in this pitiful state… seems I need to get stronger still, huh?' Commented Erza.

'Happy, why are you here? Where's Natsu?' Asked Mira.

'Natsu told me to watch Erza. As for where's Natsu…' Said Happy, before a massive explosion went off.

'That's probably him now.' Finished Happy.

Suddenly, a chill went down the spines of the newly arrived trio, along with Happy, only for Erza to look up in confusion.

"Is that Natsu? … No, that's more twisted than Natsu's… new power." Thought Erza calmly.

'My, my, what a show you all put on. I honestly never expected you to provide me with this much entertainment.' Said Master Jose, as he approached the group.

Elfman and Gray moved to confront Jose, only for Erza to feel him building up an obscene amount of power.

'No, get away!' Warned Erza, only to be too late, as a wave of energy blasted the duo away, with Mira being flung away, by the concussive force of the attack.

Erza quickly requipped into her Black Wing Armour and along with it, a single sword, with an intricate design. The blade was coloured purple and silver, with two red diamond shaped gems along the blade. Erza rushed Jose and tried to strike him down, only for Jose to avoid the attack and grab her ankle, before slamming her into the ground.

Erza quickly leapt away and faced Jose.

'You… I seem to remember… you took the full force of Jupiter head on. How can you possibly stand?' Questioned Jose.

'My comrades make my heart strong. I'm fighting for those I love. I don't care what happens to this body.' Said Erza strongly, holding her blade out in front of her.

'Such admirable strength of heart… yes, you are truly a woman worth killing.' Said Jose darkly.

Just as Jose had finished speaking, an even louder explosion rang out through the guild, gaining the attention of the two.

'What could possibly be causing Gajeel so much trouble among this guild of weaklings?' Questioned Jose in annoyance.

'You would do well not to underestimate our guild. Especially not Natsu. Natsu is even stronger than me. Gajeel has no chance against him.' Said Erza confidently.

'Such confidence. I wonder though, how would Salamander react, if I show him your mutilated body, after I kill you? Would it push him to fight even harder, or would I break the dragon's spirit? I wonder.' Queried Jose.

'Too bad you won't get the chance to find out, as I shall defeat you here and now.' Declared Erza.

'Foolish woman, you will fall here to me and Fairy Tail's dragon shall fall soon after.' Declared Jose, before the two faced off, ready to battle.

-line break-

Gajeel glared at Natsu. The transformed Dragon Slayers had been battling furiously, as evidenced by the crumbling guild around them. In a battle of dragons, collateral damage was to be expected.

'Do you really think you can win here, Gajeel?' Asked Natsu.

'I don't just think it, I know I'll crush you here today and prove who is the strongest dragon in Fiore.' Said Gajeel, before opening his mouth and spewing a spiralling wave of steel at Natsu. Natsu held his left hand out in front of him and batted the roar away, stunning Gajeel.

'You aren't going to beat me with basic Dragon Slayer magic. You need to get serious here. Fire Dragon's Wrath!' Said Natsu, before punching the ground in front of him, sending a wave of fire at Gajeel, which tore through the ground, until it exploded in the Iron Dragon Slayer's face.

'Iron Dragon's Scorn!' Bellowed Gajeel, as six crescent-shaped discs of iron, launched themselves at Natsu.

Natsu ducked the first two, before leaping over the next two, only for the last two to catch him off guard. Quickly folding his wings over his body, Natsu endured the hit and was sent crashing into the wall behind him, going through it and into the next room.

Natsu flipped in mid-air and landed safely on the ground, as Gajeel charged him. Natsu punched the air in front of him again, launching a fist of fire at Gajeel, which took him by surprise, sending him back into the other room. Natsu then rushed him and launched a knee into his gut, which he followed up, by smashing his elbow into Gajeel's jaw, sending the Iron Dragon Slayer spinning. Crashing into an undignified heap on the ground, Gajeel groaned. Gajeel quickly grabbed an iron fixture near him, seeking to get a small boost, only for Natsu to stomp down on his hand, almost breaking the bones in his hand.

'No, not this time. You'll fight with all you have now. If you cheat to get a momentary power up, I'll unleash the demon and destroy you, Black Steel. Fight me as a dragon, or die as a man.' Said Natsu, before kicking Gajeel's iron jaw, launching him back.

'That's fine, I was just getting started anyway.' Said Gajeel cockily.

'Iron Dragon's Envy.' Said Gajeel, as he clapped his hands together, causing an explosion of iron shrapnel to explode out from his hands and pepper the room in sharp metal projectiles.

Natsu gave a small groan, as he picked himself back up, feeling pieces of metal in his legs, where his wings hadn't managed to shield him.

'That was good, I'll admit that.' Complimented Natsu, to which Gajeel smirked.

'But for what you did to my guild and comrades, I won't lose here.' Said Natsu firmly.

'Guild? Comrades? Maybe you should have a look outside.' Said Gajeel, pointing to a hole in the room, which revealed the outside world.

Natsu obliged and walked over to the hole and peered out, only to freeze in shock. The guild hall he grew up in and had so many memories in, had just crumbled to the ground. His comrades were not only demoralised, but had been run ragged by Jose's shades.

"My guild… Fairy Tail… the place where I found friends, family… destroyed…" Thought Natsu slowly.

Gajeel tensed, as he felt a dark power start to come off Natsu. The malice within was palpable and caused Gajeel to involuntarily step back.

'We'll finish this later, Black Steel. Besides, you're out of time anyway and I have a new target now.' Said Natsu coldly.

Gajeel looked at Natsu in confusion, before feeling his form leaking magic, at an absurd rate. His metallic sheen was dull and started to flake off, falling apart rather quickly.

'However, if you try something like this again, don't expect any mercy.' Said Natsu, turning his right eye on Gajeel which had gone completely white, no pupil in sight, causing Gajeel to flinch.

In an instant, Natsu had ripped through the guild once again, seeking out his new target, only for a cry of pain to resound in his head, causing him to growl.

"Jose, first my guild, now her… you've hurt too many things that are important to me today. You will pay!" Thought Natsu viciously, smashing through stone and steel, as though it was paper.

-line break-

Erza huffed, standing across from Jose.

'It seems the dragons like to rampage.' Commented Jose, looking no worse for wear, after his tussle with Titania.

'I told you not to underestimate Natsu. His power matches… or even surpasses my own.' Said Erza, keeping her sword held up in defiance.

'Hm, quit with the modesty, Titania. Your magic ability is truly magnificent… in truth, no other mage has managed to last so long against me. If you hadn't endured so much damage from Jupiter, we could have had quite a battle… I just can't stand the thought… that another mage of that level, could exist in Makarov's guild.' Said Jose, before blasting Erza with another blast of his magic, sending her crashing into the wall and sending debris and rubble flying.

Erza struggled back to her feet, feeling the damage she had endured getting to her, even as Jose rambled on about his reasons for not killing Makarov and about his disdain for Fairy Tail. Erza rushed Jose, in a last ditch attempt to defeat the Guild Master, only for Jose to ensnare her with his magic.

Erza cried in pain, only for the magic holding her to suddenly dissipate and a warm feeling to wash over her.

'You have spilled much blood today. The blood of children. Thanks to a pitiful parent, children went through pain and shed many tears… this has gone far enough. I must put an end to this.' Said Makarov, only for the roof above them to cave in, as something shot through it.

'You called.' Said Natsu cheekily, confusing all but Erza.

'Who are you?' Asked Makarov, feeling the ominous magic rolling off the newcomer and wondering if he could handle both him and Jose.

'Really Gramps? I'm hurt. How could you not recognise me? Just look at my hair, even if there are horns in it now.' Said Natsu cheerfully.

'Natsu?' Exclaimed Makarov in shock.

'Natsu?' Repeated Gray, Elfman and Mira in confusion.

'Natsu.' Said Erza happily.

'Happy, Lucy is twelve floors above us. You can go get her now, Gajeel won't be a problem anymore.' Said Natsu.

'Aye sir!' Exclaimed Happy before flying off.

'I don't think so.' Said Jose, aiming an attack at the blue creature, only for Natsu to appear right next to him, gripping his outstretched left arm and aiming it down with his own.

'You've already hurt my guild, friends and my family. Do you really want to push me anymore?' Asked Natsu darkly, chilling the others, except for Erza, who felt an odd sense of safety from Natsu's words.

'Unhand me boy. You are nowhere near my level. I will crush you like a bug if you don't leave now.' Said Jose darkly.

'Will you? Fire Dragon's Grip Strike.' Said Natsu, placing his right arm over his left, before a wave of fire exploded from Natsu's hand, engulfing the Guild Master.

Makarov watched on curiously, as Jose was launched through his own guild, his clothes charred and his face red, whether from embarrassment, anger, or from the flames themselves, Makarov didn't know.

'Impudent brat! I will destroy you.' Growled Jose.

'Gramps, leave this to me. Jose has made things too personal for me today and I won't rest until I give him the beating of a lifetime.' Said Natsu, as red and black energy started to ooze out, of his respective dragon and demon transformed halves.

Jose stood up, his clothes ruffled and his expression twisted.

'Do you know why Gajeel never once disobeyed me? It was because he knew… not even a dragon could match my power.' Said Jose.

'Good thing I'm not just a dragon then. With what you did here today, I'm not just a dragon, I'm also, a demon. Dragons are protective of their kin and demons are vengeful, so what do you think is going to happen to you here today?' Retorted Natsu.

'You? A demon? You're a pink haired fool, with a penchant for destruction, but certainly no demon.' Scoffed Jose.

'You know what… I'm offended by that… so eat this, Fire Dragon's Rage.' Said Natsu, as a massive blast of dark red flames, erupted from his mouth, rushing the Guild Master.

'Shade Shield.' Said Jose, gathering his Shade magic to his hands and created a wall in front of him, to endure the attack.

Jose was fully confident that his shield would stop the attack, so he grew understandably nervous, when the shield started to crack from the attack, before the flames dissipated.

'See, you can't even touch me, you puny lizard.' Mocked Jose.

'It was a distraction.' Said Natsu, from behind Jose, before kicking the Guild Master with his right leg, which was covered in his classic orange flames.

The five onlookers could only look on in varying degrees of shock, as Natsu traded blows with the Wizard Saint. However, trading blows was rather generous to say, since Jose barely managed to attack Natsu at all, let alone land an actual blow. The Guild Master was quickly pushed on the defensive and couldn't seem to turn the tables.

'Enough of this! I will destroy you, then Makarov, then your puny guild. I am Jose Porla, Guild Master of Phantom Lord and a Wizard Saint! I won't lose to the likes of you!' Raged Jose.

'Guess what? I don't care. Fire Dragon's Roar!' Shouted Natsu, releasing his attack at the irate man.

'Dead Wave.' Said Jose, launching his dark purple beam of magic at Natsu's orange flames.

Natsu quickly stopped his attack and leapt into the air, above the two energy beams and punched his left fist at the Guild Master, launching a fist of flames at Jose, who hastily dodged.

'You're through Jose! Your guild is finished and you're a disgrace of a Guild Master!' Shouted Natsu.

'I will annihilate everything you hold dear, you impudent child!' Roared Jose.

'Just try it! Fire Dragon's Wrath!' Shouted Natsu, before launching a superman punch at the ground, in front of Jose, splitting the ground in half, as flames were launched from the point of impact, directly at the Wizard Saint.

Jose cried out in pain, as the attack struck, unable to dodge it, or raise a defence.

'Fire Dragon's Vengeful Fist!' Roared Natsu, as his fist was engulfed in dark red flames, before they were slammed into Jose Porla's torso, exploding on contact and causing immense pain, to overwhelm the Guild Master's body.

'If you ever try and attack Fairy Tail again. I won't just let you off with this.' Said Natsu, before picking up the barely conscious man, by the scruff of his collar.

'If you come after Fairy Tail again, after today… I won't just beat you. I. Will. Kill. You.' Whispered Natsu, into Jose's ear, even as he started to lose consciousness.

No one heard Natsu's declaration, except for Jose himself and despite himself, he felt something foreign to him. He felt fear. Cold fear gripped his heart in an icy grip. Jose was acutely aware as Natsu dropped him to the ground, before turning his back on him. Ignored. Defeated. The Guild Master of Phantom Lord didn't even register to the Dragon Slayer of Fairy Tail. Rage. White hot rage, not unlike the flames that had burned him previously, filled the Guild Master.

'Fool! Don't turn your back on me! Dead Wave!' Cried Jose, alarming the others, not expecting an attack from the defeated man.

Natsu turned his right eye on Jose and at that moment, the Wizard Saint froze. That single eye reflected nothing but death… and Jose was taunting the person it belonged to. Natsu raised his right arm and punched the approaching wave of energy, sending it back at Jose and blasting him into unconsciousness, as the massive explosion that the attack caused, knocked the Guild Master out for good.

At that moment, Happy descended on the scene, with Lucy in tow. Natsu smiled at the pair, before walking over to Makarov, only for Erza to make her way to Natsu first and confront him.

'Natsu…' Said Erza, momentarily at a loss for words.

'Erza.' Said Natsu, with a smile.

'All this time… you had that much power held inside of you?' Questioned Erza in shock.

'Yep and you asked for it and made me bring it out. Since I can't put it back, anymore, you need to take responsibility.' Said Natsu, with a grin, flustering the redhead.

'Take responsibility? What do you mean by that?' Asked Erza, with a blush.

'I thought I made myself pretty clear before.' Said Natsu, with a frown.

'Natsu, explain to me this instant what you mean!' Demanded Erza, causing Natsu to smirk.

'Ok.' Said Natsu, before kissing Erza again.

The group reacted in different ways. Makarov gave a small giggle, Gray looked at Natsu in shock, Elfman muttered something about Natsu being manly, Mira gave a small squeal of delight, while Lucy look as though she had missed something big, which she had, as her face was full of confusion. Happy, however, seemed to sum things up nicely.

'He likes you.' Teased Happy.

Hope you liked the chapter.

Now, since Natsu's transformation was quite intense, let me help you all visualise it.
Firstly, google "Natsu Dragneel Dragonize" for Natsu's left half. The only difference to the picture, from what I did to Natsu, is the colour and direction of his horn, which is bent inwards, midway through. Also, Natsu's face isn't covered in red scales and his eye looks like Igneel's eye, yellow with a black pupil.

Natsu's right half is a mix of Gray, when he uses his Ice Devil Slayer magic, with his black markings and the wing is similar to that of Mard Geer Tartaros, when he transforms into his demon form.

As for the horns and his tattoo on the right side of his chest, just google "Dragon Skull". It's the first image that shows up. Alternatively, google "Dragon Skull Mask", as basically all of them kink in the middle as well, as I'm trying to describe up above.

As for Gajeel, his head shifted into a humanoid form of Metalicana's, with the rest of his body, turning the same silver colour his arms turn into, in his Iron Dragon Shadow Mode.

That's all for now, thanks for reading.
SSJ3 Kyuubi Gohan.