Hello everybody and welcome to a new story called the All Devouring Slayer's Flame. This is another Fairy Tail story but this is my own idea that I don't believe I have seen anyone do before but I have seen people talk about one part of this idea on Reddit and its actually what inspired me to make this idea.

Pretty much, it talks about how Natsu ate Laxus' Lightning one and a half years before he used on Tenrou Island and guess what else happened on that island? Natsu ate God Slaying Fire. Now I know that it does sound a bit far fetched but the theory talks about how that if Natsu could make his body use the Lightning then maybe his body could adapt to the God Slaying magic as well (In my opinion it might be strengthened by the fact that he is E.N.D but hey, personal theory thing) and that he would become the Fire God Dragon Slayer!

However, what if that went one step further?

What if this theory held strong and Natsu became this... alongside eating Fire Devil Slayer flames? If this was even possible, he would become a Demonic Dragon God Slayer and that is just so damn COOL TO ME! It is just so epic and so awesome and every word for amazing that I know and so, I came up with this idea.

This will be a harem fic so just say people in the comments and I will put those people in a poll next chapter or stuff so... yeah. If that doesn't happen, I already do have a pre-existing list but hey, writers hope I guess. I don't really mind though.

So, the basic premise is that Natsu, after the battle at Tenrou goes on a 4 year training spree. In this scenario, Acnolgia does not destroy the Island but instead pose a threat to Natsu that he doesn't even know if it will happen. During this 4 year training spree, he will learn to control the God Slaying Fire that he received from Zancrow before Acnolgia attacked at Tenrou before going out to seek the Fire Devil Fire and consuming that to become the All Slayer, or Demonic Dragon God Slayer. During this time, he learns more about his dark past and about his connection to the mysterious figure Zeref as his brother and about his own abilities as E.N.D which will be bought to light. After learning that not only Zeref, but Mavis have both been under the cuse of Ankhseram for over 400 years makes Natsu vow to free his 'siblings' from their curse while protecting his Guild and his friends from threats unkown.

He is Natsu Dragneel, the All Slayer and his new goal? To kill a God.

Enjoy chapter 1.

A scowl that could set the earth a flame licked across the world.

A furrowed brow sat above onyx eyes burned heavily as they gazed across the serene landscape, which was completely the opposite of the owner's mind at the current time. Inside his skull, it was just a blazing inferno that quietly consumed him in sorrow and guilt and danced around the walls like an exotic dancer.

Natsu Dragneel felt like failure.

He had collapsed in grief and despair to the point where his body wouldn't allow him to move to protect the ones he love. Subconsciously, his teeth grit and bit into each other as his head flared with memories that sunk deep into his mind, engraved in flames that would never melt away.

The memories of how he failed on Tenrou Island.

The air leaked out of his mouth as he tried to stand, but the bones in his legs just seemed to give out and break before him which forced his body into the dirt. All around him, he just heard fighting and more fighting as dust and sand kicked up all around his fallen form. He swore that he felt Lucy or Erza or someone drag him to his feet but he wasn't concentrating on that, or the pain that dug like stone into his flesh, but instead at the towering mess that was Acnolgia.

His dark form bled across the skies and absorbed any light that even attempted to leave the island, with cyan swirls that twisted and curled unnaturally as dead white eyes glared upon them all. A smirk crossed his reptilian features as he knocked around his family, burying them deep into the earth as he flicked and flittered around the battlefield like a graceful giant; the 'grace' being removed and replaced by 'malice.'

Sound erupted around Natsu, but it was all just static to the pink haired teen as his eyes swept across the battlefield, at his family fighting and failing to gain even a little bit of power against the Chaos Dragon. The Strauss' were huddled into a corner with Mirajane trying to calm down her two siblings, who just tried to continue to fight against their broken bodies even though the barmaid wasn't fairing much better, Gajeel's Dragon Slayer instincts seemed to have activated even if he didn't realise it as he stood over a battered Levy as she heaved blood and struggled to stay conscious, Wendy was rushing around with tears flowing freely as she tried to fight against her own pain to try and heal others while Cana assisted her, the Thunder Legion were just pummelling the dragon with everything they had only to be swatted aside like wasps that wouldn't fuck off, Juvia was trying to protect the unconscious Gray and Loke who had tried to run head long at the beast before they were brutally beaten, Erza and Gildarts were really the only ones apart from Makarov that stood even a sliver of a chance in even damaging the great beast from the Apocalypse. Everyone was doing something apart from him…

"Natsu!" Twisting his head slowly, almost mechanically, the teens dark orbs joined with his partners. Lucy stared at the pinkette with worry and fear ever present through her features as her chest heaved and sank in on itself as it tried to not collapse. Happy was shivering in fear with Lisanna so at least Natsu didn't have to worry about that. "Natsu what are we going to do?!"

His eyes fell to the dirt, examining his own cuts and scrapes and bruises.

"Nothing." He was nothing at this point in time. He was a Dragon Slayer, faced with a Dragon that he could never kill. Pulling his face up from the dust, he saw that one by one everyone just fell down. Next to him, he felt the blonde fall to the ground with a *thud* as did everyone around him. And he could feel what took them all down; the pure devastating extent of the Magical Pressure breathing down onto his broken from was like the world was sitting on his back but for some reason, he never fell. But, he felt himself failing at the same time as he felt his feet stood planted into the rocks below. Glancing around, he caught his Masters eye; the old wise look of someone who just fell breathed something into his soul. Realisation.

He was alone… Against a Dragon.

It was silent apart from the dawning threat of moving feet that shook the very earth that Natsu stood.

Heavy breathing flapped against his face.

Acnolgia was staring at his body from not 5 feet away. He was smiling as his white orbs of death stared into his very soul as the thoughts of death spread across him. The air stood tense for several minutes.

Finally, the Apocalypse scoffed.

And he began to walk away, leaving Natsu stunned and fragile. Why wo-

"Take this not as a sign of mercy, Son of Igneel." The dark form twisted to meet him with a wicked glare. "Take this as a threat that will be carried out. That is, if you aren't a worthy enough opponent that is." With a dark laugh and a roar, he rocketed into the open skies.

And then he was gone.

A week on and Natsu still had no clue why he was still standing.

But he did realise one thing that day when everyone else fell; he was weak as a Dragon Slayer.

He did not blame Gajeel or Wendy because they were never heralded as the strongest Dragon Slayer in Fiore but he was and he had worn that title for many years. That title was one of the things that made him strong and pushed him to succeed… or at least he thought that it was… The top was always his friends above everything else; protecting them came first. After the top however, it was all reputation. Fairy Tail's, his friends, his own. Reputation was what made his status well known, was what made Fairy Tail… Fairy Tail. Without reputation, there Guild would just be a shack in Magnolia that had nothing to other apart from barbarians who wielded magic but with the reputation that Fairy Tail had on its shoulders, it meant that these barbarians like himself could help people and do things that others could not. It's what made showed off their strength; their status did all that before they even stepped forth onto the battlefield.

But that status had also made him cocky, made him weak.

If that's what titles got him, then to Hell with blasted names!

Throwing a ball of fire to the skies, his bone recoiled and undug themselves from each other. After their fights with Grimore Heart, they were left weak and broken before Acnolgia but everyone survived; somehow. They had come back to shore on weak waves, treading blood with them as they went back to the Guild in shame. He was lucky; his Dragon Slayer magics had helped him heal relatively quickly along with some of Wendy's help but unfortunately everyone else was hospitalised in some way or another.

And that was another sign of his weakness.

If he wasn't strong enough to protect them, which was the one thing that he prided himself for above all else then what was he? Nothing.

Sighing into the air, he slipped off the hospital rails and retreated back into the main building. Every step that he took shook his body, rippled his bandages that coated his form from head to toe but he could shove that all aside for now. His sensitive ears however were filled with noise from all over that he couldn't stop, constant ringing and screeching caused him to recoil at more than one point. None of that should have mattered though. What did matter was that he needed to do something to help prevent all this.

However, he knew that in his mind normal training regimes wouldn't cut it. Natsu needed the most extreme of the extreme, the most Hellish training on all of Fiore if he wanted to even cut it against something half the power of Acnolgia.

Just as he thought about the dread bringer, his feet stopped. The Dragons words hit his mind for the hundredth time that day.

"That is, if you aren't a worthy opponent."

Did that Dragon really expect him to fight him and be a challenge? Was that all he was in this for? The thrill? Or was it something else…

In that regard, Natsu could see it. He felt that rush when he fought a good foe like Jellal way back when or Zero and these boosts just filled him with so much drive and energy that sometimes he completely forgot about why he was there in the first place; he'd lost himself in the brawl's just to say that it was HIM that defeated the enemy so many times over the years that he wouldn't have enough digits to count them all. Then it dawned on him; if Acnolgia was really just looking for a good fight and was willing to cause this much destruction to get it, then the two of them weren't so different. The thrill… It was all consuming and had torn him away from his duties too often so… did he and the Apocalyptic Beast feel the same things?

No. No they did not.

A low growl left his throat before he ran his fingers through his messy mane of pink. Spinning on his heel, Natsu started walking over to the area of the hospital where his friends were stationed with the movements of a well-oiled machine as his mind swirled in possibilities. But this hospital was too small and confined to the point where he found his destination in mere seconds which was just too quick to get his mind under control and to stop reeling from his latent thoughts that he thought were buried long ago.

With a sigh, Natsu stared up and the door before him. Well, door was a fancy word for it: it was just a few flaps of plastic that separated him from his beaten Guild Mates. Hey, the vast number of them wouldn't fit anywhere else. That got a chuckle to emerge from his throat.

Pulling back the weightless flaps, he walked on in to his battered mates. As he showered the room with his gaze, he saw everyone turn to look at him. He gave them a nod before he started walking down the long hall. As he walked, he noticed the vast amount of people helping his broken Guild Mates out.

Alzack and Bisca were bringing food round to everyone that the Guilds new bar maiden Kinana had set out making, Jet and Droy were busy collecting supplies while Gajeel abused their deep connection to Levy in order to get himself some more metal, Macao and Wakaba were in conversation with several of the injured while Laki made some make shift splints and things for the members who were further ahead with their treatment, Redus was trying to get more paintings done of the group and Acnolgia so he could hand them over to the Council and Nab, Warren and Max were just generally bringing people towels or anything that they wanted really. It was a nice atmosphere.

'Shame that it came from something like this, though.' Natsu thought, his mind turning dark once more. He must have just stood there for a while cause soon Kinana came to speak to him.

"Um… Natsu?" The pinkette's ears picked up at the noise before he turned to meet the purple haired Guild mate.

"Um hm?" Natsu responded, waiting for her to ask her question.

"Are you alright?" For a minute, he thought about telling the girl and everyone else in the room about what ideas flowed around his head but he just forgave them: everyone needed to get as much rest without worry as possible.

"Never better, Kinana. Good job with the food." He sent her a smile before continuing to walk towards his team.

His team…

Through gritted teeth, he forced himself not to think about how they fell and instead focus on the now. Waltzing up to them, he just saw them talking with the Strauss' across from them. Keeping back, he just examined them all as they spoke.

Gray was pretty quiet but that was probably because he still had bandages wrapped around his entire form, forcing him to stay shut. At the moment, the Ice-Make mage seemed to be the only one who acknowledged that he was there, sending a silent not towards the Dragon Slayers direction. After the dumb stunt that Gray had pulled, Natsu had been helping him do common stuff for the last week no matter how much the student of Ur hated it.

Next to him sat Wendy and Carla, the duo was snuggled up together under a duvet just listening to the conversation at hand. For the last few months, it seemed hard for the young girl to fit in but she had done it despite the constant berating of her furry white companion. As he looked upon her, he felt his fists clench involuntarily as he recalled how she was worn down to exhaustion by the vast amount of times that she had to use her magic on Tenrou: how many times she hurt herself getting back up to heal more people. It made him feel useless.

Snatching his eyes away from the Dragon Slayer, Natsu focused his attention on the girls doing most of the talking; Erza and Mira. Two of the strongest women in all of Fiore as well as two of the most beautiful and most sought after but Natsu could look past that… Kind of. A sigh ran past his throat as he thought back on it. The two had made fun of him, bullied him, practically tortured him when he was younger but he couldn't see them as anything but good and great and fantastic and all the words that corresponded with 'good' that he knew! And he also remembered about how hard they fought on that damned island.

But they were both so different; Erza was just like him in most regards. She as stubborn as an ox, had absolutely unlimited willpower along with what seemed like unrestrained physical power as well but she also had her sweet sides. The beautiful red-head had just crept into his life and affected him in such a strange way but he didn't really mind the feeling, not at all.

The same went to the white haired Demon dweller. Mirajane had made such a drastic change in her life from when she was younger but with that change came a newfound connection between the two that Natsu wished the two had had since their younger years. The lack of this was mostly due to his fear, though, so he couldn't really blame the model… or could he? No matter what it was, she had snuck in as well and the two had maintained a great relationship for many years. It was just kind of unfortunate that it was built off such a dark event…

Looking back to the crowd, his gaze crossed by 3 girls sitting on a singular bed, completely ignoring the conversation at hand; Lucy, Levy and Lisanna. Hehe, 3 L's. The three were all crowded around a thick pile of paper that the Celestial mage's pencil kept bouncing on as she thought of something to write. As he looked at them, that same feeling that he felt with Erza and Mira snuck into his brain. These 3 were all beautiful, great, incredible woman. However, one quick glance to the right of the bed saw a very tired Gajeel Redfox situated to Levy's side so he just sighed before glancing back at the other two girls. White and blonde. Lisanna had been by his side for so many years and had really been the only one to even take him seriously about Igneel and she had even raised Happy (the blue cat was currently trying to talk to Carla; key word is 'trying') with him so he always saw her is some sort of holy, etheric light but after she was snatched away from him, he just felt lost. Even now, after she returned he felt that spark that was once there dissipating for whatever reason and he just fucking despised it.

Although, that may have to do with the buxom blonde situated next to her. Lucy… she was unexpected. He really didn't know what to think when he started to see her in the same light as the other 3 individuals that he already thought of but it was hard not to and he just couldn't get his head wrapped around these feelings. The Heartfilla daughter had just been there for him when shit went wrong when others couldn't and now he was just always there for her… It was a strange conundrum that made him feel strange.

Scratching his cheek, he moved back slightly before sliding down the wall until he was seated on the floor with his head at his knees. These people in his life just hit him in certain places that others could only dream of doing. Natsu didn't know how or why or any of the other W's but all he knew was that he liked these feelings. Problem was, it was happing with a multitude of people apart from these four; Cana caught his attention since they were young and the two had maintained a good friendship for years, even people like Juvia had come to his mind after he actually spoke to the blue haired girl and even Wendy whose protection he cared about so damn much just got him thinking back to some of the things Igneel taught him about when the Dragon wasn't beating him senseless.

Something about Mates…

Letting out a groan and allowing his head to collide with the wall behind him, he heard several people shuffle around before him. Opening a single eye, he looked out to see his team staring at him with confusion plaguing their features.

"Are you… alright Natsu?" Mira asked him with a small chuckle.

"And why are you sitting on the floor?" Erza added suspiciously, her eye narrowing into a glare. "Were you hiding?"

With a smirk of his own, the pinkette leapt to his feet before making his way over to the group.

"Don't worry, I feel better than ever." He replied, sitting down at the foot of Lucy's bed after giving the Iron Dragon Slayer beside Levy a nod.

"You still haven't answered why you were sitting on the floor." Erza reminded him, leaning forward in her hospital bed.

"Are you feeling sick Natsu?" Wendy asked with concern, her eyes growing wide.

"Don't be silly, child. The barbarian was the most healed out of everyone so he's fine… Unless he's gone out and got himself cursed by something which I wouldn't put past someone like him." Carla huffed, turning away from Happy once more to scoff at Natsu.

"Ow… that hurts, Carla…"

"Do you really think I care?"

"Carla!"

"Don't worry, its fine Wendy."

"Natsu!" Erza alerted the mage, drawing him out of his conversation with the Sky Maiden.

"I'm fine Erza, just needed a little rest." Twisting his head to meet the eyes of the three on the bed, he reached down to grab the stack of paper on the buxom blonde's lap. "And what do we have here?"

"Natsu!" Lucy moaned, reaching forward to grab the paper while Levy and Lisanna giggled.

"But you haven't written anything." He noted, showing the group the wordless page with a few dots and scribbles on it. "Is it invisible or something?" Natsu absentmindedly asked, getting a chuckle out of the Iron eater.

"No! I'm just having a bit of writer's block." Lucy muttered quietly before looking back to see Natsu's blank stare.

"It means that she doesn't know what to write, Natsu." Lisanna told him, giggling at his confused face. And like a light, Natsu's face lit up.

"Oh! Well I know you'll figure it out eventually." He passed her the paper with a smile, causing her cheeks to turn a low pink as she took the pages.

"So Natsu, what have you been up to while we've been in here?" Fairy Tail's barmaid asked with a sweet smile.

"Absolutely fucking nothing."

"Natsu, there is a child in your presence!"

"Ah! Sorry Erza!"

"Apologize to Wendy your idiot!"

"Sorry Wendy!"

"I-It's okay, Natsu..."

Just an average day with Fairy Tail.

Night slowly bled across the skies as Natsu watched over his friend's sleep.

All of them had slowly succumbed to their slumbers, passing out after hours of long conversations and heated discussions. Natsu… Natsu wasn't so lucky. His heart hammered inside his chest was louder than ever and the swirling thoughts in his head only got more deafening as he spent more time around his sleeping mates.

It was all just… suffocating.

Rubbing his hands over his face, he just sat back and tried to take in the world around him. The scents of vanilla, the scent of strawberries, the scent of the wild, the scent of burnt paper, the scent of rain, the scent of alcohol, the scent of perfume, the scent of steel and lightning and the earth and the EVERYTHING of his Guild. He just sat there and took it all in.

Because this was the last time that he would feel them for a while.

Slowly clambering to his feet, he felt his eyes wash over the bodies of those around him. Lucy, Lisanna, Mira, Erza, Levy, Happy, Carla, Gray, Gajeel, Laxus, the Thunder Tribe, Gildarts, Makarov… A smile crept across his face as he felt the presence of the old man; the AWAKE presence of the old man. Slowly waltzing over, he stood at the foot of the long hospital bed that held the tiny man. And just as he had expected, he saw the two eyes of Makarov Dreyar looking back at him.

"Hey Gramps." He quietly murmured, walking around the side of the bed.

"Hello Natsu, what are you doing up so late my boy?" His Master asked quizzically, but in all honesty he already knew.

"I could be asking you the same thing; you need all the rest you can in your old age." He smiled at the older man before the two relapsed into silence.

"I've seen that look in your eyes before, Natsu." Makarov's musing pulled him out of his stupor. "The eyes of guilt, of regret, of failiure."

"Gee, thanks for the reminder."

"The eyes of someone that wants to get better, to overcome what made him feel so weak. I recognise those eyes better than my own, to be honest." Looking up, he locked eyes with the teen. "And I also recognise what you must do to clear that look from your eyes."

They relapsed into silence for a while before Natsu's sniffing could be heard along with the pitter-patter of teardrops on the hard floor.

"Y-You know, I-I just thought a-a-about leaving some sort o-of note and leaving…" He tearful whispered to his Master, feeling a huge weight just become lifted from his shoulder. Natsu heard a sigh before a small but powerful hand gripped at his sleeve and he turned round to see the equally tearful face of Makarov.

"But isn't his much better, my boy? Having someone that knows of why you are doing this instead of just having that message relayed through a dull, probably unelidable piece of paper?" That got a chuckle from both mages. "So where are you thinking of going?"

"I-I honestly have no clue…"

"Try up North; It may be the place where the great Ice Mages train but it is also where many of the great Fire Mages built up their resistance to other temperatures and their own control of their magic."

"T-Thanks Gramps…" Natsu let out one last, long sigh. Before crouching down and wrapping the old man in a hug. "Remember, this isn't goodbye, okay? I'll be back someday, stronger than ever. I'll be stronger then Erza, then Gildarts, then you! Then… then nothing like what happened on Tenrou will happen to us again… Ever again." He said with conviction, trying not to break down while saying those words.

"Then we will all think of this like a job. The description; go out and become the strongest mage in the whole damn Guild. The conditions; do not return to the Guild until then. The reward; the ability to protect your loved ones for all eternity."

"Hehe, sounds like my kind of job."

"Oh trust me my boy, it truly is." Pulling away from the embrace, Natsu stood up and wiped his tears before turning back down to his Master.

"Remember to get one of the girls to watch over Happy while I'm gone okay? And make sure that he's well fed and doesn't get fish every day. Also, make sure that Macao and Wakaba go out and actually try to do something. And while you're at it, make sure to- "

"Natsu. Go." Makarov chuckled at his 'child' as the pinkette began to back away, casting one last look over his Guild, his family.

"If I didn't know any better, I would assume that your trying to get rid of me Gramps."

"To know that, you would have to be smarter than a pile of rocks."

"Haha, good one. Well… I'm off on that job now… So… seeya, for now."

"I'll be waiting, Natsu. Good luck."

The two, master and student, 'father' and 'son', gave one last nod of consideration to each other before Natsu turned around and stormed out of the hospital and Makarov buried his face into his bed sheets to hide the floodgates that had opened on their faces.

And then Natsu Dragneel was gone.

Thanks for reading.

-Jack