Here we go another chapter of probably my favourite fic that I'm writing at the moment. At any rate I hope you enjoy this chapter as much as all the others because this story is fast becoming one of my most popular and demanding for updates. Oh yeah I wrote this chapter while listening to Hiroyuki Sawano Perfect time on an endless loop so that may have influenced things a bit so yeah on with the story.

"It's been a while, child of the Flame Dragon King"

"Impossible! how are you even alive, I killed you?!" Natsu shouted at the smug demon standing before him. "Come now you know there's only one obvious answer" Mard said causing Natsu to grit his teeth. "So how many pieces did you take?" Natsu asked although he didn't exactly want to hear the answer especially when he saw Mard's smirk widen.

"All eight pawn pieces, five of which became what I understand are known as mutation pieces" the underworld king said in an even tone, "It's improved my base powers dramatically both physically and my curses; but that's only the surface my etherious forms has grown in leaps and bounds beyond anything you or I could imagine!" Mard Geer said in a deranged voice as he began radiating his curse power which was now mixed with devil magic.

"So you're a stray now, what did you with the devil who brought you back?" Natsu asked in a slightly nervous way. He knew the answer he would get but his nervousness was caused by the power Mard Geer was radiating, it was immense and if his etherious form had gotten even stronger then he had to assume at full strength Mard would be on equal terms with him.

"I was feeling a bit merciful at the time so I allowed her too live but I killed whatever other members of members of her peerage there were" Mard said with a tinge of anger in his voice making Natsu grit his teeth in frustration. "Sayla did you get that, if so relay that and anything else you find important on this matter to Rias and her lot they might know something that can help us" Natsu communicated with his demon companion telepathically who was still currently in the middle of fighting.

"Okay but I'm a little busy trying to keep all these golems from getting to you" Sayla replied as she blasted another golem into rubble before punching her fist through another's head. "She a lowly devil that thought she had the right to make me the underworld king her servant, truly pitiful; although I will admit that I am grateful that she brought me back for now I can exact my revenge for the humiliating defeat I suffered at your hands" Mard said with a scoff as he began walking towards Natsu before stopping only a few feet away.

"Oh I believe this is what you're looking for" the demon said before giving a swipe of his hand causing two magical circles to appear at the far end of the room reveal Kuroka and Koneko bound to the wall by chains but otherwise unharmed.

"KUROKA!"

"I assure you she and her sister are quite unharmed, I have no interest in them I just needed them to get you here" the demon said before Kuroka and Shirone started to awaken. "N-Natsu?" Kuroka mumbled out in tired voice "Hang tight Kuroka I'll finish this quick" Natsu said before he blinked once and the demon's markings appeared over a large portion of the right side of his face and neck causing Mard Geer to quirk an eyebrow. "I see he's awakened some of his powers" the demon thought before a smile crept on to his face.

"I see, you're going to be serious from the get go; if that's the case then I will too!" the demon shouted before changing to his etherious form and charging in on Natsu in a blur. He was so fast Natsu was barely able to get his guard up in time to stop the haymaker that would have collided with his right temple surprising the dragonslayer greatly.

"Come now don't tell me I'm too fast for yo…ugh" Mard began to mock the slayer before he was silenced with a knee to his jaw sending his head reeling back. "Yes, yes that's it this wouldn't be any fun if you just stood there and took it" the demon king said in a deranged battle crazed tone upon recovering from the blow.

"Tch, guess it's not just your powers that were increased but your physical abilities as well huh?" Natsu said with annoyance clearly evident in his voice causing Mard Geer to smirk. "I haven't been able to think of anything other how I would take my revenge; all this time I've been bidding my time understanding this world, gathering information increasing my power all for this day!" the demon shouted as he clenched his clawed fist in satisfaction.

"Well I'm here in front of you right now, give it your best shot" Natsu replied taunting the underworld king with a hand gesture making the demon smirk before the two charged at one another.

"Soul Punisher!"

"Fire Dragon's Iron Fist!"

The two fighters shouted out, Natsu using one of his signature attacks mixing it with a bit of his black flames while it looked like Mard cloaked his fist in what appeared to be a white flame. As the two collided a tremendous shockwave resounded throughout the area momentarily distracting Sayla before she had to refocus her attention back on the immediate threat that was the army of golems.

"Wow, what the hell was that?" Issei shouted donning his balance breaker while fending off a golem, "Its trouble, that's what it is" Sayla said through gritted teeth and she used her raw physical strength to punch straight through one of the golems impressing Rias and her peerage.

"Tch with the number of them here we're gonna get nowhere like this, looks like I'm gonna have to get serious" Sayla said in a serious tone confusing the others by what she meant. "ETHERIOUS FORM!" with a roar a surge of power erupted from Sayla resulting in her appearance changing.

Her curved horns were now elongated and more straightened and her skin had taken on a darker tone, more tattoos were now visible on her body as her entire upper torso was exposed resulting in one perverted devil almost dying from either blood loss, getting distracted by the gracious view or by his overly clingy jealous master.

Sayla's legs had changed as well, now they donned a more peg like appearance making her slightly taller. "What's sort of a demonic transformation is this?" Akeno asked in surprise but her king could only shake her head.

Back with Natsu and Mard Geer the force from the blow had sent both fighters skidding back a considerable amount. "That isn't fire, it may look like it but it's different; I can't chance eating it, not when I'm against this guy of all people" Natsu thought to himself before quickly recomposing himself, entering his partial demonic transformation and charging at Mard.

"Hoh a head-on attack like that won't do any good" Mard said with a confident smirk as he raised his hand and the same white flame like energy appeared before it shot off towards the dragonslayer. "If you really prepared as much as you said then you'd know that I have a few new tricks up my sleeve too!" Natsu shouted in response as the black markings travelled down along his right arm in order to make its usual broken blade shape.

"FULL COUNTER!"

To Mard's surprise his own attack was reflected back at him at twice the speed as well as twice the power leaving the demon king with only option of using his wings to shield him from his own attack. The resulting explosion from the impact shook the tower like structure greatly but even at that Natsu knew this battle was only beginning.

"Hahahaha" "It's always maniacal laughter before they dramatically reveal they aren't hurt at all" Natsu thought to himself in an annoyed. True enough he could see Mard Geer's silhouette making its way out of the smoke before with a flap of his wings he dispersed the smoke and dust showing that just like the pinkette thought he was uninjured.

"I must admit, that is an interesting technique you have there but I shouldn't be surprised you had such a technique, you never were one for sharing your techniques with the rest of us; well except for her" Mard said in a even tone confusing Natsu. "What does that even mean, why would I share my techniques with my enemy?" Natsu asked in confusion, he may not have been the brightest spark but Mard Geer just wasn't making sense.

"So that's how it is, he's awakened some of powers but has retained none of his memories; interesting" Mard thought to himself as a smile made its way across his lips. "Nothing, it doesn't exactly concern you per say" Mard replied which increased the confusion felt by the dragonslayer.

"You say you have some tricks up your sleeve but I do too" Mard said before reveal a set of devil wings along with his regular ones. "Now you see me…" the demon said just as he fizzled out of sight, "What the uggghhhh!" Natsu was about exclaim when a well planted kick to the side of the head sent him flying. "Now you don't" Mard said in an amused tone as he watched Natsu crash into a wall.

"Lightning Flame Dragon Mode!" Natsu shout in anger as his demonic markings spread further, red and black fire enveloped his body as well as purple and golden lightning arcing around his body. This peeked Mard's interest, especially when he noticed the storm clouds gathering overhead. "I wonder how long you can keep that form up, if you're using that with the intention to keep up with me then all I'd have to do is outlast you" Mard said with a narrowed gaze before his senses went on full danger alert.

The demon just barely managed to duck underneath an electrified flaming punch allowing him to deliver a punch of his own to Natsu's abdomen. However, before his fist could connect Natsu grabbed the demon's fist by the wrist with his free hand. "Sorry buddy but I like to get up close and personal in my fights" Natsu said in an almost demonic voice.

"Lightning Flame Dragon's Nova Hammer!"

Slugging the demon as hard as possible Natsu sent Mard flying in a ball of fire and lightning. When Mard came to a stop he got up this time his face showed signs of injury as the flesh around the area Natsu struct was burnt away and smouldering making the dragonslayer smirk. But the smirk was short lived when he noticed the flesh slowly repair itself.

"I'll admit that one actually hurt quite a bit, unfortunately for you my ability to heal was also enhanced upon reincarnation so that's another advantage I have over you" Mard said in an overly confident tone. "Now it's my turn!" the demon shouted rushing towards the slayer. "Who said my turn was over, now take this"

"LIGHTNING FLAME DRAGON'S RRROOOAAARRR!"

Just like the time he showed Kuroka Natsu' roar was even larger than before and his demonic black flames and purple lightning was mixed through his regular fire. The breath attack was so wide Mard has no chance of dodging and was swallowed whole by the attack before it burst out the back of the tower and continued off into the horizon.

"Master really isn't pulling any stops today" Sayla muttered to herself as she fired a blue energy beam through several of the golems. "I'll admit he certainly is impressive" a new but familiar voice said causing Sayla to turn behind her. "Sirzechs?" she questioned with a confused look n her face.

"Brother why are you here, I thought you were gonna leave this to us?" Rias asked upon noticing her brother who shook his head in response. "No we couldn't leave something like this to you guys it would have been too dangerous, besides what we needed was for you guys to buy me sometime while me and a close friend sorted out a plan of action" Sirzechs replied in an even tone as he watched the roar fade out.

"Crap, whew been a while since I've used that hah" Natsu panted out feeling the drawback from using such a powerful attack. "Come on, I know that didn't finish you off" Natsu called out narrowing his eyes on the unmoving slightly disfigured silhouette in the smoke. "Uggghhhhhaaaaaaa" Grunts of pain were all the slaver heard before the smoke cleared revealed Mard Geer covered in severe burns, some of which were so bad the skin or skin like armour was still melting off his body in various places. Perhaps worst of all was the fact both his devil wings had been burnt off and membrane of his main wings was torn in all sorts of places.

"Oh I see now, the more damaged you are the energy you have to exhaust in order to heal it, so that means there's a limit to which you'll be able to heal yourself right?" Natsu less asked more stated as the demon fully regrew his missing appendages and healed his injuries. "Alright then let's see you take this then!"

"Advanced Dragonslayer Secret Art; Crimson Lotus Exploding Lightning Blade!"

Natsu shouted as he charged forward gathering the lightning and flames around his arms, but before he could move them in the circular pattern Mard grabbed both his arms locking them in place meaning Natsu was unable to complete the spell. "Shit!" the slayer cursed out before the demon executed a well planted head butt causing the flames and lightning to disperse revealing Mard's hand to be severely burned.

Not giving the slayer a chance for a breather Mard delivered a fierce barrage of punches and kicks before flinging him up into the sky, "Yddrasil!" upon shouting this a portal opened a few metres above Natsu before a massive plant like column erupted out from it and crashed into Natsu's back, smashing him through a floor or two of the two.

"Damn he's far more powerful than before, I've got no choice I'll have to use that!" Natsu thought to himself before he jump back up to where the demon stood with a triumphant look on his face. Falling to one knee, clutching his arm in pain and making it look like his demonic powers had faded out Natsu left himself completely open. "Guess you were all bark no bite, son of Igneel" Mard said pissing Natsu off slightly before using a powerful blast mixed with his curse power and newly acquired devil powers and slamming it down on top of Natsu like a whip.

"What's wrong with him why isn't he using his reflecting power?" Koneko asked her sister. From what she had seen of the man he should have been able to match the demon in front of them but the sight in front of them was quite the opposite, Natsu was being dominated in every aspect of the battle. Or at least that was Koneko's view on the battle, "I don't know this has never happened before, his powers have never just left him like that" Kuroka answered her sister.

"Ugh" Natsu could only grit his teeth to bear the pain as Mard Geer flew along with him in his claws grinding his face along the floor lifting up stone and brick alike before finally throwing him up into the air and flying quickly above Natsu and delivering an axle kick sending him through one of the floors in the tower causing him to cough up a small amount of blood.

"What's the matter dragon boy? Not fighting back, too scared? Or have you just accepted that you're totally outclassed in this fight!" Mard Geer shouted as he barraged Natsu with assault after assault of endless energy blasts causing him to grunt in pain as he was forced down through more floors of the tower.

"In your dreams pal, I'm nowhere near through with this fight yet!" Natsu grunted out through clenched teeth as he jumped back up to Mard Geer but the next thing he knew was that he was being flung across to the opposite side of the building crashing through several pillars and walls curtesy of another energy blast.

"Master are you alright, the link between us is fading out" Sayla asked through the mind link she set up with Natsu. "It's fine never mind me just take care of the enemies on your end but be safe" Natsu communicated back telepathically as he pushed his way through the rubble that fell on him. His attention was then refocused on the incoming Mard Geer.

"Oh you can't imagine how much I've longed for my revenge; I couldn't care less about lord Zeref all I've cared about since our last encounter was the chance to get my revenge with my very own hands" Mard said as he started walking towards Natsu.

Said dragonslayer started walking towards the demon in front of him, the two began to quicken their pace before they were at full on sprint towards one another. "Thorns" Mard suddenly called out causing multiple tendrils of thorns to shoot out of the ground, two of which pierced Natsu through his right leg and left arm halting him in his track before Mard delivered another punch to Natsu's face "Uugghh…fuck this is probably the worst plan ever" Natsu whispered to himself

"This can't be all you're capable of Dragonslayer, I demand satisfaction" the demon shouted only to get a strained laugh in response, "Sorry, hate to disappoint you, but I've been feeling under the weather lately" Natsu response in fake amusement before spiting blood to the side causing Mard Geer to grit his teeth in frustration, "then there no point in continuing this, DIE!" the stray shouted before gathering all his power in his outstretched palm and firing at Natsu.

From the outside Rias, her peerage, the Satans and Sayla could feel the power from the blast connecting with Natsu. "What the hell was that!?" Issei shouted in shock as he shielded his friends (the girls) from the shockwave. "That must have been that demon, he's more powerful than I anticipated" Sirzechs said as he sent another wave of destruction magic to take out more of the golems.

"If you have a plan Ajuka I'd love to hear it" the crimson haired Satan said through a red communication circle to his fellow super devil as he punched another Golem in the head causing it to crumble. "I'm working on it!" Ajuka replied before a green barrier raced forward crashing through multiple golems.

Natsu stood shakily with Mard Geer glaring at him, even though the slayers body was badly burnt and bleeding which was a first for Natsu. He could feel the pain his broken ribs were causing him just from breathing but right now this was his only plan. Mard Geer's regenerative abilities were just too great for Natsu to deal any significant damage in one decisive blow. "How pitiful you truly look in this moment, your father would be ashamed" Mard mocked as he strode slowly towards the slayer.

However, the demon missed the smirk present on his face. "How much? How much is all that power worth I wonder, let's find out" Natsu said in an amused tone before a golden pillar of light erupted around him completely blowing the top of the tower off as it continued to the sky. The shockwave of which halted devil and golem alike in their fighting but none were more so surprised than Mard Geer.

"What's with this insane power…It couldn't be?" the stray thought to himself before his eyes widened in realisation, "He took all those hits on purpose!" the demon thought in shock before he began gritting his teeth

"Oh yes it can, REVENGE COUNTER!" Natsu revealed shocking everyone in the process as the magic power continued to swirl around the dragonslayer and reach towards the sky. The devils all stared in awe at the power being displayed in front of them wondering what exactly was going on, that is until Sayla decided to explain.

"Deactivating his demonic powers Natsu purposely took the attacks of the enemy storing the power up within his body, the power continues to build until it becomes unstable effectively turning himself into a bomb; however, this technique is considered a double-edged sword that endangers the life of the caster as well, survival rate from the energy accumulated for both is less than 1%" Sayla explained much to the shock of Rias and her peerage.

"Such a technique actually exists?" Sirzechs asked in awe, "Yes, it is the one technique that must only ever use in the direst of circumstances, if master was unable to accumulate enough energy then he may not be able to defeat the enemy" Sayla added in a worried voice.

"No, no I've come too far to lose to the likes of you, to lose to the same person a second time!" Mard Geer shouted as he charged towards Natsu who gritted his teeth. "Sorry bub but you should've stayed dead the first time now take this!" the dragonslayer shouted in response before throwing his fist forward causing the golden pillar of light to envelop Mard Geer forcing him back further and further until he was no longer visible. The resulting explosion was colossal and it shook the tower to it's very core even causing large parts of it to fall from the side. Everyone watched as Natsu fell onto the floor barely breathing with all sorts of injuries littering his body.

With whatever little energy Natsu had left he activate his demonic powers long to heal his injuries to a neglectable standard. He then slowly got to his feet and then made his way over to Shirone and Kuroka before breaking their bindings and releasing them. "You should make your way back to your friends Shirone" Kuroka said as she held Natsu up. "I'm sorry" Koneko suddenly said surprising her sister, "What for?" Kuroka asked as she slung Natsu's arm over her shoulder. "For all the mean things I said about you, none of it was true; everything you did was for me" Koneko said in a saddened tone as tears began pooling in the corner of her eyes.

"Idiot, if it meant that you could live I was willing to become the villain for my little sister" Kuroka said in a caring tone before flicking Koneko on the forehead "Owe". "Now go, your friends are waiting for you" Kuroka said before her sister spread her devil wings and took off to where said friends were. "Look at you trying to act all cool in front of your little sister" Natsu said in a strained amused voice before Kuroka turned him around so that she was now facing his chest in order to hug him. "You really are a reckless idiot, but you're my reckless idiot" Kuroka said in a content tone but before Natsu could say anything in response he felt an indescribable pain pierce through him.

Lifting his head up he could only widen his eyes at the sight before him

"Impossible"

Chapter end

Okay you can bash me all you want for revenge counter but what were you expecting I already said that there was heavy influence from the seven deadly sins as for the way in which it was used I'm hoping you can get that I was trying to come at this in a sort of Dragon ball angle with a specific fight in mind. At any rate I hope you enjoyed this chapter it took me three times to get it the way I wanted it.