Training Begins:

5 Years later:

The Gremory family is one of the remaining Devil Families of 72 Pillars and one of the highest-ranking and famous Devil families. They are ranked at Duke. The members of the Gremory family are all characterized by their red hair color and powerful magic talent. The Gremory family are beings with extraordinary affection among the Devils. As such, they do not discriminate against their servants. The Gremory family is also famous for the production of current 'Lucifer' Sirzechs.

Speaking of Sirzechs, we can currently find the aforementioned Lucifer running down the halls of the Gremory mansion along with his son Naruto. Both of them were running like their very lives depended on it.

In the last 5 years, Naruto has grown a lot. His red hair is styled in a neat combover style that his mother forced him into wearing. His face was a bit round due to his age. He is currently wearing a plain black t-shirt, white shorts, white and red Reebok shoes, and short black socks.

The reason behind their hysteric running is-

"Come back here you two and take your punishment like men!" Came to a clearly enraged female shout from behind them.

Hearing the shout both father and son duo redoubled their efforts with absolutely terrified looks on their faces.

"Come on dad do something! You are her husband, go and stop her or she will catch up with us soon, and then there will be hell to pay! Go and take your punishment dad!" Naruto yelled over to his father who was also running like Yahweh himself was on his ass.

"What?! You go and take the punishment! This was your idea anyway! I warned you what will happen if she finds out!" Sirzechs yelled back in an even more terrified tone all the while trying to lose the she-devil trailing them.

"I don't remember you saying that! In fact, if I remember correctly then it was you who was pressuring me into this." Naruto yelled as he tried to speed up his pace.

So much were the pair of father and son distracted in their shouting and running that they totally missed an ice wall blocking their path and face slammed into it. Falling down pathetically, the duo slowly turned around and saw a horrifying scene in front of them, causing them to hug each other and scream out like little girls.

Standing in front of them was Grayfia. Her once beautiful silver hairs were dyed orange and her clothes were an odd mixture of pink and yellow. She was tapping her left foot in anger. She also had her arms folded under her bust giving her an image of a pissed-off woman, which was an understatement.

"Well, what do you both have to say for yourself huh?" She asked in a low tone, frightening both of them even more of the upcoming doom.

Suddenly an idea came to Naruto's mind and he quickly untangled himself from his father and looked up at his mother with tears in the corners of his eyes.

"I am sorry mommy, I tried to say no but dad just forced me to take part in it. I will not do it again mommy." Naruto said in the best sad tone that he could muster at that moment with a fake tear running down his face.

All of the anger quickly fled from Grayfia's face after seeing her son's look and she immediately went down to her knees scooping Naruto in a tight hug all the while saying, "Don't worry baby it's alright. I know it wasn't your fault. Your father is a mean man and I will make sure to punish him extra hard for dragging you into this. Now what do you say, honey, do you want to eat some pizza?"

"Ok, mommy. But please don't hurt dad too much, he was just probably trying to play with me since he is mostly busy and only has very little time to play." Naruto said still with the tears in his eyes, causing Grayfia to hug him even more tightly.

"My little baby is so understanding. If only your father could be as smart as you." She said, glaring at the still cowering Sirzechs completely missing the wink and teasing look her son was sending towards his father as if saying 'You are in for it now sucker'.

"B-B-But Grayfia-chan it was Naruto's idea to prank you, I am just an innocent person stuck in the wrong place!" Sirzechs tried to defend himself but only ended up getting glared at even harder.

"Is that so, I see you need to be disciplined properly Lord Sirzechs." Grayfia said in an emotionless tone freaking out both the males present there with Naruto now sending his father a sympathetic look.

"Fleur AN:1, can you please take Naruto to his room and prepare some ramen for him. Oh and make sure that he takes his bath first." Grayfia called out loudly and as being magically summoned, a beautiful girl who looked to be in her early teens appeared behind her.

She had waist-length, long pink hair with straight bangs covering her forehead and a pair of red horns on her head, and a white limiter headband over her horns. She had sharp, turquoise eyes with rings around the pupils and pinkish-red markings on the canthi. She was wearing a customary maid outfit nearly identical to Grayfia.

Her full name was Fleur Lucifige, the adopted little sister of Grayfia. Who found her in a crater as a little girl full of bruises old and new showing a life of abuse with no memories of her past, Grayfia who was reminded of her own traumatic past, instantly took the girl in. At first, the girl was very self-aware about herself and had no name, only a tag that said 002. It was extremely hard but Grayfia eventually broke down the walls she built around herself and gave her the name Fleur which means Flower in French.

Fleur is also an apprentice of Grayfia so she just like her teacher/sister specializes in Ice spells though that does not mean that Ice spells are all she knew. She also has the ability to drain energy and she has a good grasp of martial arts too. She is also Naruto's personal maid as well as his bodyguard.

"Of course Madam, I am always happy to be of any assistance." Fleur said as she bowed her head to the 'head maid' then turned and bowed towards Sirzechs and Naruto.

"Good, take Naruto to his room, I have a husband to punish for trying to corrupt my son," Grayfia said as she finally let go of Naruto and moved towards Sirzechs who was trying to claw his way through the ice wall when she pinched his right cheek and dragged him down the hall all the while ignoring the current Lucifer pleaded to let go of his cheek.

Naruto and Fleur could only watch the antics of 'The Strongest Couple of Underworld'.

Finally, having had enough, Naruto turned towards his personal maid and said, "Fleur, let's go and have some pizza. I am really hungry right now."

Looking towards her master, Fleur smiled and replied, "As you wish Lord Naruto but first let's go take a bath shall we."

"Ahhh but I am so hungry. I can take a bath later. Come on, please make me pizza already.", Naruto whined wanting to eat pizza as soon as possible.

"If that's what you want then I will do just that Lord Naruto but first I will have to ask for your mother's permission seeing as it was her who gave me the order to give you a bath first. Do you want me to go and ask for her permission, Lord Naruto?", Fleur asked in a deceptively innocent tone causing Naruto to go stiff at the mere thought of angering his mother and he was sure that this time even his tears won't work against her either.

"No, no, no need to get mom involved in this Fleur. I was just joking around, Let's go and take a bath.", Naruto exclaimed with a fake cheer and ran towards his room to dodge his mother's wrath.

LINEBREAK

Sometime later in the evening:

After the whole prank fiasco, Sirzechs returned to his office with his Queen/wife standing dutifully at his side while in front of them stood a member of his peerage.

The person in front of them appeared to be a man in his late twenties. He was wearing a traditional Shisengumi uniform, which consists of a haori and hakama over a kimono with a white Tasuki crossed over his chest and tied in the back. The haori was colored light blue and the sleeves were trimmed with light mountain strips.

This man's name was Souji Okita and he was Sirzechs knight.

"Are you hundred percent sure about this Souji?", Sirzechs asked in a serious tone. His demeanor was totally different from what it was early in the morning. Right now there was no playfulness in his attitude and his whole presence screamed power. The power that can not only bring destruction to almost all those whom he wished to harm but can also erase their very existence from the face of the earth.

"Yes Lord Sirzechs, I am one hundred percent sure about this. There is a terrorist organization known as 'Khaos Brigade' in motion and The Old Satan faction is a part of it. By now you must have deduced that their goal has to do something with world domination. Which means that they will do anything and use any means to attain their goals and Lord Naruto can be one of their targets too, being the biological son of Lord Isshiki himself even if that information is strictly confidential but secrets of these kinds tend to come out sooner or later.", Souji explained in a grave tone, knowing the effect this terrorist organization can have on the already fragile peace between the factions and the mayhem a group of dangerous terrorists can cause, especially if they get their hands on someone with the potential to surpass even the most powerful being in existence AN:2.

Standing behind Sirzechs silently till now Grayfia had an emotionless look on her face but anyone who knew her better can tell that she was greatly troubled by the news and worried for her son's well-being. Her fists were clenched tightly at her sides and from time to time a muscle would jump on her jaw indicating that she was gritting her teeth too.

Looking towards Souji, Grayfia said in a low tone but was clearly heard by the other members of the room very clearly, "I will never allow anyone to get their filthy hands on my son. I will die before I will ever let anything happen to him."

Yes, she was very possessive of Naruto. It does not matter if they were blood-related or not. He was her son and she will be damned if she will let anything happen to him.

Looking towards his wife, Sirzechs smiled at her response to this news. It was good to see his normally stoic wife act so passionate towards anyone. In these past 5 years, he had seen a totally different side of Grayfia and he has to say, he was liking it more and more. Motherhood definitely suits her.

"Don't worry Grayfia, I won't let anything happen to him as long as I am alive either. He is our son and I will personally destroy this whole organization if I have to just to ensure his safety.", Sirzechs said, gaining a small smile from his wife in response before he looked towards his knight and continued, "Now Souji, tell me everything that we know about this organization."

Nodding in response, Souji replied, "Yes Lord Sirzechs. Well from what we know, this organization is divided into various segments and the Old Satan faction is one of them. Other than that all we know is that it also contains rogue mages, fallen angels, and exorcists. The identity of their leader still eludes us but he/ she has to be someone very powerful to be able to control such chaotic people."

Humming in response Sirzechs contemplated on the information he was provided with and thought of ways to handle this problem without starting another great war.

While he was busy with his line of thoughts, Souji suddenly said, "Lord Sirzechs if you don't mind, I would like to suggest that we should train Lord Naruto now. It will make it harder for anyone to hurt him if he has a good grasp of his powers. Whether we want to acknowledge it or not, he is an Otsutsuki, and sooner or later he is going to be in harm's way. It will be good if he can handle himself at that time. We can not possibly be there to guard him all the time."

Listening to what Souji was suggesting, Grayfia immediately interrupted, stopping Sirzechs before he could formulate his own response, "Absolutely not. He is still too young to start training. We never got to have our own proper childhood, I don't want my son to lose his either."

Standing up from his seat Sirzechs turned towards Grayfia and spoke in a serious tone, making it clear that what he has to say is not something to be debated on, "I know where you are coming from Grayfia but what Souji is saying also holds a lot of merits. We won't be taking away his childhood, the situation is way different so that won't happen, but you have to understand that it is for his own safety that he knows how to not only protect himself but also his precious people. That child has more raw energy than me when I was fighting at the beginning of the civil war. If we do not teach him how to use it properly then it can prove to be dangerous to everyone around him. Plus I can sense that he has inherited 'Power of Destruction' from Amelia. It seems to have mutated, however, making it even more important to start his training now."

Hearing her husband's words, all Grayfia could do was give a small nod even though the frown on her face was making it clear that she does not like the idea of training her baby who is only 5 years old. 'Someone his age should be playing with toys, not training to master his power.' However, even she has to admit that it will be great to know that Naruto can handle himself out there especially with this danger looming over their heads.

"Good, now please go and inform Naruto that his training starts tomorrow morning at 7 AM and that I will be personally training him myself. On the few occasions where I will not be able to do so, you will have to take over his training for me Grayfia. I am sure he will be ecstatic after hearing this news as he has been pestering me to train him as of lately.", Sirzechs ordered as he turned to discuss some other business with his knight while Grayfia gave a small bow and went on to complete the task given to her.

LINEBREAK

Next day 7 AM:

True to Sirzechs words, Naruto was extremely excited when he heard that he will be starting his training and under the guidance of his father at that, who was known as one of the strongest devils in existence.

He was determined to surpass his father and knew that in order to do so he had to train very hard and he would do just that. There was no way that he was going to give up his dream of surpassing his father, no matter how hard he has to train, no matter how much pain he will have to suffer. He will persevere through it all and he will achieve his goal no matter what.

It was early in the morning and we could already see the father and son duo standing opposite sides to each other in one of Sirzechs's personal training grounds. After all, even a Satan has to train in order to keep his skills sharp. Standing a few meters away from them were Grayfia and Harmosa who were observing the duo and were present to provide any sort of assistance that could be required from them.

Looking at his son, Sirzechs said in a completely serious tone, "Okay Naruto, listen well. While we are training I will forget that you are my son and you will forget that I am your father. During our training time, you will refer to me as Sir. I will not be going easy on you so if you have any second thoughts about our training then tell me now because once we start I will stop at nothing. Do you understand?"

Gaining a determined look on his face, Naruto brought his fist up to his face level and spoke with great confidence, "I am not afraid of you or your training and one day I am going to surpass you no matter what. So bring it on and do your worst, because I am not going to give up old man. That's a promise of a lifetime!"

As soon as he finished speaking, Naruto was bonked on the top of his head by his father who yelled comically, "Who are you calling old you brat? I will let you know that I am very much a young man! And what did I say about calling me anything other than Sir during training."

After that Sirzechs stood up straight and smiled a bit, his mood changing like the bipolar person he is, and said, "Though I like your confidence. Let's see how far you can maintain it. Naruto, what is magic?"

Naruto answered back instantly, "Magic is a mystical force that everything has access to, it is only limited by imagination, knowledge, and reserves. Certain species like devils, angels, yokai, gods, and other 'mythical creatures' have an advantage over learning magic due to higher reserves and biological knowledge presets caused by previous generations of magic users, such as the Bael's power of destruction or the angels' light magic. However, gods are given a domain from what people worship them as, for example, Zeus God of Thunder, or Shiva God of Destruction."

Sirzechs shook his head not expecting his son to answer the question so detailedly and said, "Okay, very well done. Now, what can you tell me about the general power ranking system?"

Naruto instantly answered yet again, "The general ranking system is what gives people a letter-based rank based on destructive capabilities, each exponentially more powerful than the next. It goes as follows:

F-Rank- No destructive capabilities.

E-Rank- Human-level destructive capacity.

D-Rank- Non-Reinforced wall level.

C-Rank- Building level to Town level.

B-Rank- City level to Mountain range level.

A-Rank- Country-level to multi-Country level

S-Rank- Continental

S+-Rank- Moon level

SS-Rank- Planet level

SS+-Rank- Star Level to Solar System Level

Z-Rank- Galaxy level to Universe level

Z+-Rank- Multiverse level

ZZ-Rank- Higher-dimensional

ZZ+-Rank- Boundless level

However anything Z+-Rank and above is mere speculation until further proof. I have to ask, father, what rank are you?"

"Very well done son, I am SS-Ranked but I am one of the strongest people in the macrocosm. In fact, I am the 8th strongest being in them.", he finished as his son looked at him in amazement. Before he continued, "Now sit down cross-legged in a meditation position and then close your eyes and concentrate inwards. Try to spot your energy and when you do, grab onto it and summon it outside of your body, as much as you can."

Listening to his father, Naruto immediately sat down in the meditation position Harmosa taught him and focused while trying to locate his energy.

Locating it was pretty easy, as even he could sense how large his energy pool was. Though grabbing it and summoning it outside was a totally different case due to the chaotic nature of his energy, he kept on trying, and finally after what felt like hours to him but were only a few seconds, in reality, he was able to summon his energy.

Since his eyes were closed Naruto was not able to see everyone's reaction to his energy, which varied from shock to awe to pride.

Finally opening his eyes Naruto looked down at his body and saw it being surrounded by black and silver-colored energy pillar that extended into the sky farther than the even enhanced eye can see while also creating massive cracks in the ground that spanned the entire training ground only stopping when it reached the barrier at the end of the field AN:3. Grinning like a fool he looked up towards his father and mother and yelled in excitement, "Look, mom, dad, I did it, I summoned my energy. Woohoo, it feels awesome, I feel so strong-"

Before he could continue his rant, he was bonked on top of his head once again, effectively cutting off his energy flow and bringing him down from his energy rush, and knocking him down.

Looking up he saw that it was Sirzechs who had bonked him once again.

Clearly agitated by this action of his father's, Naruto jumped back onto his feet and yelled, "What's the big idea old man! I just summoned my energy didn't I?"

Only to be bonked once again and fall down again. While Sirzechs was once again yelling comically, "Don't call me old! I am not old! I told you to call me Sir, didn't I!" And once again he got serious immediately making Naruto think that his father must have had some of his screws loose before he heard Sirzechs saying, "As for why I did that? Well, Naruto you have to understand that you have lots of energy and as you will learn in the future, just exerting this much raw power out can have negative effects on other people who are not used to being in the presence of this level of energy. Just look at what it did to Fleur."

Meanwhile, he was thinking 'That was on par with an S-ranked warrior power and his power of destruction is black instead of red. It must be some of the power he inherited from Isshiki-sama. We must bring this to Ajuka when we take him to get his peerage pieces.'

And true to his father's words, just as Naruto looked in the direction of his personal maid, he saw her sitting on her knees with her hands on the ground and panting hard as if she had just run in a marathon with her power limited to E-Rank. Drops of sweat were trickling down from her face and in front of her was a barrier erected courtesy of his mother.

Seeing what he had unconsciously done to his best friend and maid caused him to feel so much guilt that he could only utter, "I-I-I d-didn't I-I-" Until he felt a hand on top of his head and ruffled his hair. Looking up he saw that it was his father who was ruffling his hair with a warm smile on his face.

"Don't worry too much kiddo. Just keep in mind that this power that you have can bring just as much harm to your friends as it can be to your foes. What you did right now was amazing and I am very proud of you but you have to understand that in order to not hurt your friends, you have to learn how to control your powers. Which I am pretty sure you can do as I myself had once faced this problem but when I learned how to control it properly, I became that much more effective in combat and less of a danger to my friends. When you summoned your power, you also used your Power of Destruction by mistake, which led to this situation. However, now that we know what we have to do, we can overcome every problem. Remember that we are always here for you and will always help. All I ask from you is that you give it your hundred percent while training and I promise to you that you will see the fruits that hard work can bear in the future. So what do you say, son? Are you really ready to train properly now?" Sirzechs said in a warm fatherly manner, soothing some of Naruto's worries.

As he turned towards Fleur once more, he saw that she had recovered now and was standing once again though her face was an emotionless mask as she started walking towards him. Coming to a stop as she reached her conclusion. The beautiful girl once again went down to her in front of her master and bowed her head low before Naruto could even say anything, "I am sorry Lord Naruto. Please forgive me for my weakness. I am supposed to be your bodyguard and I can't even withstand the pressure of your power, it's pathetic. I swear to you, please just give me one more chance and I will get strong enough to be able to stand by your side!", Fleur said as tears started to fall from her eyes, feeling utterly pathetic for being weak even after all her training.

Naruto is just there in shock, not being able to understand how someone else can blame themselves for his mistake. It was his fault that Fleur had to go through that. He should be the one apologizing, not her!

Taking his silence as a rejection of her apology, Fleur began to feel a sense of dread rising within her. What if her weakness had pushed Lord Naruto away from her? She had not said anything yet but Lord Naruto was very precious to her. He was her first and only friend. It was because of him that she even started training under her aunt. What will she do if he decides that he wants someone else as his bodyguard? Wha-

Her line of thoughts was short when she felt two small hands on her head forcing her to sit up and look at her master. What she saw surprised her a great deal. Sitting in front of her, giving her a teary smile was her master. His eyes shined with determination despite few tears visible in them.

"I should be the one saying sorry Fleur. It's my fault that this happened and for a second there I thought that you would be afraid of me but I am thankful that I was wrong. I promise to you that I will get my power under control and will continue to grow stronger and stronger. All I need from you is a promise to be there with me forever and to never leave my side. We will grow stronger together. So what do you say, Fleur, do you want to give it a shot?", Naruto said with such sincerity that it left her flabbergasted.

Coming out of her shock Fleur suddenly lunged forward and hugged Naruto tightly which he returned wholeheartedly. Sobbing some more, Fleur replied, "I swear to you, Lord Naruto. I will always be by your side. It's a promise of a lifetime."

Standing a small distance away from the hugging duo were Sirzechs and Grayfia, smiling at the heartfelt scene in front of them. They are so proud of their son that they can't even begin to express it. Grayfia tried to go and comfort her son but was stopped by Sirzechs who shook his head, saying that this will help both Naruto and Fluer to grow stronger both physically and mentally and will strengthen their bond.

So they silently left the two for a bit so that they can have some alone time all the while wondering what the future has in store for them.

Chapter End

AN:1 Fleur is the name I gave Zero two because it won't work in this story.

AN:2 As far as they know, Isshiki was the strongest being in existence. They don't know about the other Otsutsuki.

AN:3 Training ground with a ruin barrier around it was made to withstand the full power of Sirzechs.