During his stay in Dragon Mountains Issei missed many things, especially after his residency in Tannin's cave was cut short. He didn't blame his trainer for this, he understood that dragon's family safety takes priority over his convenience and that housing someone who's energy can explode at any time again is as far as it gets from it, but he was just a teenager thrown into rather extreme conditions away from his home for the first time in his life.

Obviously, he missed his parents and friends, the time he spent with them relaxing or goofing around. He missed meals prepared by his mom, his computer, his bed and pillow... He simply missed his life back home and the comfort it offered.

He also missed few things he would not have expected, like school (boring lessons are better than running away from a dragon), being beaten by Kendo Club (getting hit by a wooden sword swung by a girl is much more enjoyable than getting hit by a spiked dragon tail), and his alarm clock. He didn't miss being wakened up early, that was still present, rather he missed the way it did it. Who wouldn't prefer the voice of beautiful girl over the roar of a dragon or explosion next to you? Even if they were just recordings based on romance archetypes and he didn't know the girls they were still better. Yes, even yandere one threatening to burn his bed jealous of his relationship with it. If only because his alarm clock couldn't burn his bed, dragons on the other hand...

Not that Tannin ever did. While he dubbed it [unnecessary luxury] and mocked him for his choice of the bed near forest over a cave, he respected his decision. That's why when his bed started getting warm he presumed it was just the sun heating it, it might've been the first time he wasn't wakened up before dawn. But when the temperature kept rising he opened his eyes and looked around only to found his bed burning!

He jumped out of his bed like it was on fire... OK, it was, but it's still good description... And yelled at his trainer.

"Old man, what the... Tiamat-sama?" He noticed that the dragon next to him wasn't his trainer. That explained why the flames were blue.

"I see Tannin exaggerated how luxurious your camp is." Tiamat said looking around.

'Luxurious?!' Issei thought shocked. His camp contained: bed made of sacks filled with grass, which just burned... bonfire and small stack of wood so he didn't have to use his flames when he's too tired, table and chair or at least that's how he called the boulders that he chiseled a little to act as them, and that's it. Only [luxury] you can find here would be a waterfall nearby which acted as a shower...

"Before you ask, yes, I'm here to train you. And yes, Tannin will be back later to help.
Rules. If you want my help you will do everything I say, exactly like I say and you won't question anything, but you'll answer any questions I may have. Is that clear?"

"Yes, Tiamat-sama. Thank you." Issei was almost crying from relief at this point.

"Before we start, I want one thing from you. Promise me... No, swear an oath that you will not fight Albion's vessel-"

"No. I won't jeopardize my friends and family safety like that." Issei interrupted.

"As much as I admire your dedication to protect them, let me finish, vessel of Ddraig." Tiamat growled making Issei swallow heavily.

"Swear an oath that you will not fight Albion's vessel if you can avoid it. Swear that you won't attack him when he shows up, you won't react to his taunts nor will you provoke him to attack first. I don't want you to run from him, but I want you to at least try to avoid conflict. If he attacks you or your friends then you can do whatever you want."

"I told you earlier, I won't seek a fight with him. I swear I won't do anything to start a conflict between us."

"Great." Tiamat had an evil grin on her face. "Now, run!"

And with that, his training under Tiamat began. At first, Issei was confident, after all, running away from Tannin was base of his training so far, but he was wrong. He thought that Tannin was a monster, but if that was true, then he didn't have a word to describe Tiamat.

It didn't matter how inhuman and harsh Blaze Meteor Dragon's ways of training were, Chaos Karma Dragon had even more twisted and sadistic equivalent.

Running away from a dragon? Immensely harder when said dragon didn't give you a headstart and was actually aiming directly at you and not in your general direction. Issei learned it the hard way when a fireball explosion sent him flying into a tree. When he was getting up he expected a little breather and some time to resume his escape as usual, but he was met with a lighting hitting the ground next to his feet and a shout [Did I tell you to stop?!].

Tiamat also didn't limit herself to fire. He tried to hide in the forest and use trees as a way to interrupt fireballs? Lightning quickly found its way to him. He tried to hide behind a massive boulder? Even larger one was thrown at him. Or she simply dived at him and attacked him with her tail or claws.

Jogging with a boulder tied to your back? Apparently, it's the wrong approach as it didn't train your muscles evenly (who knew?). Instead, Tiamat enchanted his clothes. She didn't change their mass, she changed their weight or even more accurately, the force they exerted on Issei but not his surroundings. If he were to stand on the scale it would show his normal weight, but he felt like he was wearing cloaths made from lead. She told him to wear them all the time and that she will adjust their weight for different exercises. Also, jogging is boring, so you should expect being attacked from time to time or that your jog will turn into steeplechase without a warning.

Weightlifting was deemed unnecessary, Tiamat said that she will just increase the weight of his clothes as he progresses.

Training with magic was postponed until he'll train his body but Tiamat mentioned that she will implement it into his jogging rather than separate exercise.

On top of that, she extended the training session to the point that Issei was afraid that exhaustion will kill him faster than his condition... That is if Tiamat won't do it even faster.

And she said that she expects that he'll be ready for a proper fight with her in just a few days. Issei was already scared what kind of beating he will receive.

His life turned even worse because of that. He trained until he passed out and when he woke up he trained again. He was sure that he didn't go to sleep during this period and only breaks were for him to eat something.

The training continued for the next two weeks with only four interesting events.

After four days Tiamat had stopped referring to him as the vessel of Ddraig and called him Issei for the first time. Although, she still refused to call Ddraig anything but Welsh Asshole and pretended that he didn't exist unless she wanted something from him.

His first fight with Chaos Karma Dragon went better than expected: he actually survived her first strike but second sent him into in the arms of Morpheus.

Somewhere during the second week of training (he lost his track of time due to his [irregular sleeping schedule]) he woke up in unusual conditions. Normally after he passed out Tiamat waited nearby or left the area, but this time when he opened his eyes he found her lying next to him using her wing to cover him. But when he asked her about it she tried to dodge the question by throwing a fireball at him and reminding him that he's not allowed to ask questions. He didn't raise that subject again.

The last thing was... Issei found a scale.

.

.

.

Surprising, isn't it? He found a scale in the Dragon Mountains in the area where he was constantly accompanied by at least one dragon. What are the chances of something like that? However, it has more sense when you take into consideration where exactly he found it.

It was small red scale with sharp edges, located between his shoulder blades.

At first, Issei thought that the pain he felt was a result of his physical training (read: beating he received) but it turned out there was more to it. It seemed that Ddraig was right and fusion of his demonic energy and dragon fire indeed caused him to grow scales. According to him, Issei's body was reacting to Tiamat's energy, but there was nothing to worry about; the energy was distributed evenly throughout his body which was storing and slowly imbibing it without any problems. As his training went on, the tempo of the reaction escalated, but since Issei never said anything Welsh Dragon assumed that everything was still fine. And it seemed that it reached the level where it started altering his body directly and turning it into dragon equivalent. However, it raised a question what the final effects of it will be. Will he turn into a dragon or humanoid dragon? Or maybe the transformation won't be complete and he'll turn into abomination with parts of his body being dragon-like and parts human/human looking devil?

Ddraig didn't have an answer. None of his previous hosts turned into a dragon via exposition to dragon energy, it only happened in the Juggernaut Drive and then it was almost instantaneous process changing their whole body at once. And it ended up killing them... But while his current host situation was different, it didn't explain why despite possessing the same amount of dragon energy in the whole body only parts had transformed. Was it because of his devil side and demonic energy?

Unfortunately, neither of dragons, even Tannin who was a devil himself, knew that, but they all agreed that the best, for now, would be to continue his training. Unfortunately again, it lasted for three more days before he wasn't able to continue. When the changes reached his internal organs and the pain became unbearable dragons called for help.

Sirzechs Lucifer stepped out from a magic circle and walked towards Tannin. He didn't know why he was asked to come here, but he was sure it's something important and bad, otherwise, the dragon wouldn't bother him.

The Devil King hoped that he was wrong and it was good news or at least it wasn't something too serious so he could help. He loved his sister and had big plans for the boy, but he couldn't risk his position as a Maou, not with Old Satan Faction recent activity.

"Tannin-dono. You wanted to see me?" he greeted the dragon.

"Ah, Lucifer-sama. Yes, we require your assistance-" Tannin began his explanation but was interrupted by a pale-blue haired woman who walked straight to Sirzechs and poked him in the chest.

"Bring me Beelzebub. Now." she said and walked away.

"Tiamat-dono?" Lucifer asked surprised but she ignored him and disappeared behind a barrier, so he turned back to Tannin "How did you convince her to help?"

"I didn't, hatchling did, but he doesn't know how. He said that she refused, and yet she showed up next day looking for him." dragon shrugged "However if I had to guess I'd say it has something to do with how she started to refer to him as her hatchling."

Lucifer's eyes widen and he barely kept his mouth closed. The wellbeing of the Sekiryuutei had just become number one priority, even if he had to make it official. Because no matter how badly Rias would react if something happened to the boy, or she found out that they were lying to her, the consequences would only affect his family, but Tiamat's involvement was a threat for the entire Underworld.

Of course, he was confident that if the things turned for the worst he would defeat Chaos Karma Dragon, especially with other Satans help, but the damage to Hell would be severe. And if dragons take it as a declaration of war and rebel, or other factions use that as their chance to eliminate Devils... There may not be Hell left to rule.

Sirzechs shook his head to clear his thoughts, there's no point in thinking about the worst outcome when he didn't even know what the problem was. He followed Tiamat sending a message to Ajuka on the way.

He was impressed by the quality of the concealment barrier behind which Tiamat had disappeared. He, the strongest devil alive, could barely sense anything standing next to it. And while he wasn't the best in espionage and scouting as he was more of a fighter during the war and both Serafall and Ajuka would probably sense it easier, it still said a lot about the caster.

It was also his third warning, after dragon's message and Tiamat's behavior, that something is terribly wrong, otherwise, there wasn't any reason for such barrier to be erected other than to keep Tiamat's involvement a secret. But he doubted it, they were in the Dragon Mountains and Chaos Karma Dragon had every right to be here, the barrier was too small to hide them during training, and it would be a too nice coincidence that his arrival and the barrier weren't connected.

His last warning came in form of expensive and comfortable looking king-size bed he saw after he had crossed the barrier. He didn't know much about Tiamat, but dragons as the species believed in a concept of tough love and training their young ones in harsh conditions until they were strong enough to get what they wanted by themselves. It was a reason why they had ruled the world before the Dragon Hunt and such bed definitely didn't fit that culture.

Most of Lucifer's questions were answered by the state of the boy lying on the bed. He was shirtless and it showed his well-built body, the time spend training truly did wonders for his muscles. Although, it was everything good Devil King could say, the rest wasn't pleasant. The boy was pale, his unnaturally twisted body was covered in sweat and rash, scales were scattered across his skin. His left arm was fully covered in them and his hand looked more like a claw, and the same could be said about his right leg, which was longer, thicker and was bend forward rather than lying flat on the bed. As Lucifer got closer he barely held back a wince when he saw the boy's face. Apart from grimace of pain, it didn't look human-like. His left eye was reptilian, its blue color shone from the reflected dim light, but his right eye was still human and brown. His lower part of the face from nose to jaw was extended forward forming small snout, but his skin and scales haven't covered its whole giving clear sight of the mingled human teeth and dragon fangs, which gave him a rather unnerving look. To worsen his hideous appearance, he had lost most of his hairs and was growing horns.

Lucifer now understood what the problem was and was sure about two things: the boy must have been in unimaginable pain and his little Ria-tan can't see him like this or learn anything about his condition. But he had no idea how it happened or even what exactly happened.

Obviously, the [Pawn] was slowly changing into a dragon, but what sort of a dragon? And what did it mean for his Evil Pieces? Will he reject his Pieces and became purely dragon? Will he keep his demonic energy fused with his fire? Will he become dragon devil hybrid? Maybe something like Buné Clan?

Sirzechs shook his head to clean his thoughts again. Whatever happened he probably won't be able to deduce it just from looking at the boy. And with Ajuka coming in shortly he should worry about boy's condition more as the answers will come later. He willed his smile back to his face and approached the boy, who immediately tried to stand up when he saw Devil King earning a glare from Tiamat.

"Don't stand up, Issei-kun, there's no need for that" Sirzechs said.

"Lucifer-sama, it's a pleasure seeing you, but, if I may, what brings you here?" Issei asked. Or at least tried to but his forming snout and irregular teeth turned his speech into an almost incomprehensible mumble making it hard for Sirzechs to understand him.

The Devil King didn't comment it, it wasn't boy's fault and pointing this out wouldn't change anything, it would only make him feel worse. However, his question made Lucifer curious. He was asked to come here but it seemed that the boy didn't know this. He glimpsed at Tiamat and the look she gave him confirmed it.

"I heard about your condition and came to see if I can help with something. How do you feel, Issei-kun?"

"I... I am fine, Lucifer-sama. Thank you for asking."

"Yeah, I can see that." Sirzechs chuckled. "Let's forget that I am Devil King for a moment and tell me how do you really feel."

"Terrible." Issei sighed and slumped down onto the bed. "I have a migraine from a different kind of vision in each eye and my hearing switching between almost deaf and supersensitive. My whole body is burning, especially my skin, and even the slightest movement makes it worse. Growing a tail also isn't a pleasant feeling. But I am not dying, so there's that."

"You should've asked my father to send you some painkillers or some stronger anesthetic."

"If I believed it could help I would." Tiamat responded with a voice cold as tundra. "He's a dragon and that means he's immune, or at least highly resistant right now, to all poisons, and as nice as it sounds, it also means that he's immune to most conventional drugs and I don't want you to experiment on him. I brought herbs that help reduce pain but there's only so much they can do."

Reluctant to poke an angry dragon Lucifer backed off with simple "Sorry, I didn't know" and watch in disbelief how Tiamat affectionately brushed Issei's hair. Not so long ago he had to spend two hours to convince her that, whatever Welsh Dragon had done, going after his current host wasn't worth getting into conflict with the Underworld, and now? She was acting like an overprotective mother would with her sick child. What in the Hell happened?

Before he decided whether or not he should voice his thought Ajuka walked into the barrier.

"Sirzechs, what is so important that- Oh, hello Tiamat." Beelzebul tried to ask.

In response, she rushed to him, grab his collar and pulled him to the bed.

"His Pieces are acting up. Fix them." she growled.

Satan glanced at his friend looking for an explanation, but Lucifer only mouthed "later." He shrugged and turned to the boy and poked his finger at dragon's chest creating many small magic-circles to examine his pieces.

"So, Tiamat, here's where you've been past two weeks, huh? Surprising, I thought you said [I want nothing from Sekiryutei other than watch him die], what changed?" he tried to start a conversation.

"Less talking, more fixing."

"I have to examine them thoroughly to avoid any mistakes and I am fully capable of having small talk with you at the same time, so what changed?"

"I... I... He... That's none of your business."

"I guess not, I was just curious." Beelzebub shrugged and turned to Issei. "Looks like you are trying to do something interesting. I wonder-"

"Can you fix his pieces or not?" Tiamat interrupted.

"I can't fix what isn't broken. But I've made some modifications that should help."

"Great, then leave. My hatchling needs rest."

Ajuka's eyes widen and he looked at Sirzechs silently asking what she meant, but Lucifer only shrugged and gestured his friend to follow him leaving dragons alone.

"What did you find?"

"Two things. One which we should've foreseen, it was obvious that fusing dragon fire with demonic energy would affect his pieces."

"Maybe for you, I still don't have any idea what you are talking about since you had never bothered to explain how your creation works" Lucifer defended himself.

"I did!" Sirzechs shook his head. "Really? Huh, whatever. Pieces were designed to coexist with any powers or species traits that recipient possess but also to not interfere with them to avoid any complications. Like Tannin's [Queen] piece had no effect on his dragon fire. But in this case, there's a direct connection between his pieces and dragon fire and it opened them to the influence of dragon energy that also comes from his Longinus. It's affecting the power of chess pieces. The trait is being used on something else and is changing a bit, but the effects are too small to say what exactly it is."

"I see, we have to keep a close eye on him. And the other thing?"

"He's trying to use part of the pieces used to resurrect recipients as devils."

"What!? But he is a devil and pieces can't be used again."

"The thing is when your sister resurrected him she used eight pieces, but it was mostly a price for his Longinus and the spirit of Welsh Dragon, it was a buffer for his potential, but only one piece was used to change him into a devil the rest was sealed."

"Yes, I know, I was there with you when he said about it and Ria-tan mentioned it earlier."

"No, not that seal. I am talking about an automatic seal inside [Evil Pieces] that is activated when multiple pieces are used. It locks the spell and unused energy used to turn recipient into a devil. He's trying to get past the seals in the [Pawns] and use that energy to turn himself into a dragon. Or rather a dragon-devil hybrid as he will most likely keep devil's traits."

"I agree, that's interesting. But also troublesome. What did you do with his pieces?"

"I altered them slightly so they won't malfunction due to messy overwritten code and so they send me an update from time to time. I also lessen the seals so he'd have freer access to the energy in them. I considered removing it entirely, but seeing his condition I'm not sure he would survive that."

"And now?"

"I don't know, it's something new, I have no idea what the result will be. I'd have to run some tests, but I don't think Tiamat will agree. Speaking of which, what's her deal?"

"I don't know much more than you." Sirzechs sighed tiredly. "Issei asked her for help and she agreed for the unknown reason. Tannin's theory is that it has something to do with how she refers to him as her hatchling, but I don't know why she does that."

"Hmmm. I have a theory that may explain most of what is happening, but I'm not sure if it's good news."

"Shoot. I doubt it can be that bad."

"He's not changing into a dragon, he's being reborn as one with Welsh and Chaos Karma Dragons as parents."

"But... Reborn? How?..."

"First dragons were born from pure energy and I could sense energies of both of them in his body next to his. Welsh's is easily explained by his Longinus or his wings but it doesn't make sense for Tiamat's energy."

"I take my words back. If something happens to the boy it will be worse than I imagined."

"Yes, we have to ensure little Dragon Prince safety."

"Dragon Prince? I don't think dragons have such title." Sirzechs tilted his head confused.

"Well, there wasn't a child of Emperor and Queen earlier."

"Tiamat is a Dragon King and I think that they don't treat that titles as royalty rather as a sign of respect."

"Either way," Ajuka waved his hand dismissively. "we have to make sure he'll make through that change alive so Tiamat won't blame us. What's your plan?"

"I'll take him to my parents." Sirzechs said. Soon after the words left his mouth he turned pale and his shoulders slumped.

"What's wrong?" Ajuka asked more intrigued than worried.

"I have to convince overprotective dragon-mama that she has to entrust her son safety and health to devils because she can't take care of him alone. And if I fail, or I succeed but something still happens to him, she has enough power to destroy Hell in revenge."

"Oh, that." Beelzebub laughed. "Yeah, leave it for your sister to bring you troubles that affect whole Underworld."

"And here I thought he was the first member of her peerage that didn't cause the international crisis by joining it. Not her fault though, she only wanted to save them, I can't blame her for it." Lucifer smiled.

"Good luck with convincing her, I'll get back to my lab and see what can I find about his condition and what can we do to help."

With that, he disappeared and Lucifer walked back to dragons.

Issei opened his eyes in his mindscape confused. He didn't know how he got here, maybe Ddraig took him here after he fell asleep?

"Hey Ddraig, what happened?" he asked dragon lying next to him.

"What's the last thing you remember?" Welsh Dragon responded frightening him, nothing good ever followed such question.

"I was... I was playing a board game with Millicas in my room, I think." Issei said after a moment of thinking.

"Your transformation reached your heart when you were sitting with Young Fake-Lucifer. Good news is that it means that it's almost finished, you survived the worst part and you will be fine, however, your reaction to it was rather violent."

"Ddraig. What. Happened."

"Your energy exploded and you're technically in the coma since I brought your consciousness here, but don't worry, like I said, you'll be perfectly fine. You'll wake up as a healthy dragon and-"

"What happened to Millicas?" Issei interrupted.

"Oh, that's what you're worried about. Nothing, at least nothing serious. You threw him outside the barrier before the explosion. He hit the wall quite hard, but I'm sure that devils will agree that it was a better outcome than staying inside."

Issei released his breath he didn't realize he was holding. "That bad?"

"You annihilated everything inside the barrier, so yeah, that bad." Ddraig smirked.

"At least no one was hurt, I'll take that as a victory. Sooooo...
What now?"

"Like I said, you'll wake up as a healthy dragon, but... I don't know how long it'll take and I cannot really interact with outside world; I waited too long to bring you here and we're kind of stuck here."

"What do you mean?" Issei asked nervously.

"Well... I should've taken control earlier, but I saw how you wanted to make sure the boy is out of the barrier and, um... I was a little too late. As a result, the explosion threw your consciousness deep into your soul and I was pulled with you. I can try to go back, but there's a risk that you'll follow and... *sigh* There's no good way of saying this. The transformation is painful and the only reason you don't feel any of it is that you're basically disconnected from your body. If your consciousness follows me-"

"I'll feel the pain. No, thank you, I think I've felt enough of it recently, I'll take a coma."

"My thoughts exactly."

Issei looked around only to see that nothing changed. It was still empty grassland except the two of them.

"What can we do to kill time in here?"

"We can train."

"I meant something fun, Ddraig..." Issei sighed.

"Well, we can fight but I considered it as the part of the training, so..." dragon shrugged.

"Yeah... no. I'd like to rest a little. What are you doing when I'm not here?"

"Not much, sleep, sometimes watch what you are doing if it's something interesting, or I watch battles of my previous hosts."

"You jest." Issei watched Welsh dragon in disbelieve who shook his head. "Damn, you really don't have much in your life... I'll have to do something about this. But now I'm stuck here as you said, so... Are the battles your host memories? Like the one you showed me mine from the Rating Game?"

"Aye. And some mine own from before the imprisonment."

"We can start with watching some and then we'll think what to do next." Issei suggested with a smile making Ddraig laugh. "What?"

"That is what I meant by training or the first step of it at least. Obviously, you can't train your body in here, but I can show you different techniques of my previous hosts and you can practice them here. When you wake up you'll have to learn again how to perform them, but, as long as your body is capable of performing them, it'll be more like remembering moves you haven't use in a while rather than learning them from the beginning."

"Huh, sounds awesome!" Issei beamed.

"I know, I am amazing, you don't have to say it." Ddraig chuckled. "Let's start with Belzard, he was the strongest Red Dragon Emperor in history and killed two White-Ones. It will show you how badass you can become, but I expect you to surpass him." 'My son' Ddraig finished in his thoughts.

AN.

Happy new year!

I could post it earlier, but I wanted to end up with Issei back in Kuoh. However, I have troubles writing parts of it (like his talk with his parents) and I'm not sure when it will be ready. And I kind of promised myself that I'll post the chapter in 2017... only little over two and half hour late, yey... Well, it's still 2017 in America so it counts.

A cookie for Primordialdragon who said in review what is happening to Tiamat :)
On that note, please don't ask questions from guest accounts. Not that I don't appreciate them, 'cuz I do, but I don't have any way to respond to you and it makes me feel bad :(