The Knight of Ruin(DxD)

The next two weeks were the same as usual for Romonus. He spent a lot of his time training in control over his Demonic Energy, strengthening his body, and learning in the library. He had memories of a few useful rituals he would use later on which would give him useful abilities. 

Of course, when he was older he was far from skilled enough to use any of them. But at the two-week mark, Zeoticus called him from the Library to his office. Romonus closed the Ritual Book he had been reading after memorizing a few useful rituals. 

He put the books back before he ran to his Father's office. When he opened the door, Zeoticus was talking with a beautiful woman. 

"Romonus, remember when I said I would get you an instructor? I found you a good one, her name is Petellia Dardanius. A Reincarnated Devil Mage."

(Image here)

Romonus gave a polite bow to her. 

"Hello, I am Romonus." 

She smiled as she kneeled to be at his eye level. 

"You are quite polite, Romonus. As your Father said, I will be in charge of your education until you are 5 years old and I will teach you all I know. Including how to use your Powers. By the way, Lord Gremory, it seems his Demonic Power is active."

'How did she-?'

He got his answer when he saw her eyes covered in a magic circle. She had scanned him and she had seen that his Demonic Energy was not stagnant. Zeoticus turned to him. 

"Son, have you been using your Powers?" 

"Yes. It was easy." 

He raised his hand as he pictured his Demonic Energy combusting into Fire. In his hand, a large flame began to burn. Petellia analyzed his level of control and found it to be very good for his age. 

"You are quite talented at that. Lord Gremory, does the boy have his Bloodline abilities?" 

"He does. Both Bael and Gremory. We tested him at birth." 

"Has he ever used his Power of Destruction then?" 

"No, we told him to not use it. It is dangerous for a boy like him to use it." 

Petellia hummed as he turned off the fire. 

"I can work with this. I will teach him what I know and how to use his powers including his Bloodline abilities. Is this alright?" 

Zeoticus looked at Romonus who had made his eyes look as cute as he could. 

"Please, Dad." 

Zeoticus smiled as he relented. 

"Alright." 

Romonus smiled as he ran to his Father who caught him in a hug. Zeoticus turned to Petellia who already planning what to instruct Romonus and how to train him. 

"Will you only instruct Romonus only, or Rias as well?" 

She turned to Zeoticus with a polite smile. 

"You only paid for Romonus." 

Zeoticus cleared his voice. 

"In that case, I can pay the same for you to instruct her." 

"In that case yes, but if she is slower than Romonus you need to understand that." 

"Of course."

Petellia then turned to Romonus. 

"Are you ready for your first lesson in magic?" 

"Yes, Ma'am." 

"Follow me then." 

Romonus waved goodbye to his dad as he followed the magician lady. As they were walking, she kept quiet as she was going to see how he used his magic to plan out a training regiment. He was just happy to get a proper instructor now rather than guessing his way through. 

"Romonus, I want to ask you what kind of Devil do you want to become?" 

He thought about it as he always wanted to use a sword or some other weapon.

"A Sword Mage." 

He could use magic from up close, long-range, or get in close and personal to hack and dice. 

"I can teach you the Magic aspect, but for swords, I would ask your brother's Knight. Lord Sirzechs has the strongest peerage in the Underworld after all." 

"Cool." 

Petellia led him back to the library where she asked him to sit down. 

"First, we will talk about human magic and then Devil Magic. For humans, we require calculations that are based on Devil Magic. But Devils only require imagination and control over their energy. Of course, being unimaginative will weaken your magic so get creative. 

Today we will just go over what you know." 

Romonus nodded as he sat down in his chair as he always did. In his cultivator pose with his hands on his legs. As he did so, from his body he began to release the energy which formed his strings again. By this point, he had 20, but the 21st was uneven. 

Petellia seemed quite surprised to see what he was doing so she asked him about this. 

"What is this?" 

"My training." 

"I can see the merit, each 'string' is a line of your Power and to keep it steady takes up energy from you. You also train in multitasking and control. Who taught you this?" 

He smiled proudly as he answered. 

"Me." 

Now she looked surprised. Controlling 20 different lines of Energy could not be easy and he was making it seem effortless. When she considered his young age it was amazing. 

"You invented this method?'

He nodded with a smile. 

"All me." 

She smiled as she realized her job would be easier then she expected. 

"That makes things easier if you have your method. I have a few spells that could help with your multitasking or even your overall control. But from what I can see you only have trained in control and not in using it. I will remedy that. Are you ready?" 

"Yes." 

"Excellent. I will teach you one I used as a mage apprentice. Form a fire floating in front of you." 

He focused as his strings dissipated, but the energy in them gathered and formed a small fire. Once it was burning she crossed her arms. 

"Orbit it around your body." 

Romonus did as she instructed which was a training method in another story. As she watched how easily he did it. 

"Add more until you begin to have trouble." 

He created more balls of fire which kept orbiting around him. He eventually stopped at 16 as controlling anymore was becoming increasingly tricky. Seeing how well he was making them spin impressed her. 

"Incredible control. You can stop." 

He snuffed out the fires as she smiled. 

"You will certainly be a terrifying Devil in the future if this is how good you are as a three-year-old. Here is to hope your sister is just as skillful." 

'Doubtful.' 

Seeing his weirded-out expression, Petellia realized something. 

"She doesn't even know how to use her Power does she?" 

He nodded causing her to sigh. 

"This is going to be annoying won't it?" 

He nodded with a chuckle. Seeing how happy he was made her smile. 

"Well then, we got time." 

This was how Romonus got introduced to proper magic and information. Rias ended up getting dragged along with him, but just as Petellia had said she was a headache. She always wanted to run off and play, she would dose off, and she did not like her head hurting which was going to happen when using her magic. 

But since she was getting paid, Petellia endured the spoiled nature of Noble children like Rias often Romonus was the opposite as he sat still in his lectures, he did not good off and he listened. Rias only lasted in her lessons for a month before she was excused out of lack of interest by her Father. 

Zeoticus was disappointed, but since Rias was three it was to be expected. Romonus was just an outlier since he was not an actual child. But, just as Petellia had recommended, Romonus asked his older brother Sirzechs if his Knight Souji could train him in sword fighting. 

Petellia only was his instructor for two years before she was no longer needed as Sirzechs got someone better to teach him. His Bishop, MacGregor Mathers was considered one of if not the best Mage in the Underworld. 

Petellia did not mind as she still got paid and she felt she had gotten him ready on his path. He thanked her for her time and he never saw her again after that. Instead, his time was consumed by Souji who trained him in the art of the sword, Mathers in Magic, and Surtr Second in physical combat. 

The three servants of his older brother were always open to mentoring him as he was open to learning everything they had to teach. He had come a long way since the early days when he was working on getting a feel for his energy as now he had it under control. 

He was a different beast than when he had been born and it showed. 

---

Romonus flipped open his journal as he sat in a fancy chair in his room. He and Rias no longer shared a room as he had asked to have his room 5 years ago. It had been granted and Rias rarely went into his room. 

His room had everything he could need, a shelf for books, and workout equipment constructed out of Demonic Energy. He also had a custom alchemy, and chemistry set in one. He also had a weapon rack where he could place the swords that he created like the one resting at his side. 

It was heavier than most Longswords, but not quite a Greatsword. Souji had wanted him to use a Katana, but he was much more partial to the heavy style of a heavier-than-normal long sword. 

He had made it himself out of Magisteel which he had forged from metal he had soaked in his blood, compressed with Gravity, tempered in Power of Destruction, and forged in fire fueled by his Demonic Energy. Thanks to that the sword could resist the Power of Destruction. 

(Image here)

Over the years, when Surtr second learned of his affinity for Gravity magic he had forced him to use it on himself like in Dragon Ball. Or the knockoff version that existed in DxD which he could not remember the name of. 

It had led him to have an incredible physique for one as young as him which had been forged by Surtr and Souji. Just as he was reading through a few rituals he had been planning on undergoing, the door to his room opened. 

He glanced up and saw that it was a maid. He had not learned her name as she was just another one of his Father's girls. There were hundreds of them and each one as forgettable as the last. 

"What is it?"

She bowed politely toward him. 

"Young Master, today is your 11th birthday and the madam is asking you to present yourself to the guests when they arrive." 

He grunted as he reached out for his sword. 

"She also asked you to not bring the sword and to dress in more formal attire. You are always in your battle attire and she feels you will look better in formal wear for your birthday."

(His Outfit.)

He glanced up with a squint in his eyes which caused them to glow a deep purple. It was not a trick he had actively created as it had started to happen when he got annoyed or angry. Mathers assumed it was because of the constant circulation and purity of his energy. 

At this point by relying on his bloodline and extreme training, he had already entered the Ultimate Class. Being the son of Venelana Bael, Zeoticus Gremory, and his stronger soul thanks to being a reincarnator he grew his power quickly. 

Of course, he was going through the same issue that Rias went through in canon as everyone said it was because of his clan, his brother, or his parents. He ignored such statements as they were just that. Statements. 

"Alright. You can go." 

This maid had just been added to the harem half a year ago for her great body, but it was worthless to him. Her power was less than even a Low-Class Devil as she was just a commoner Devil who was lucky to be pretty. 

"Of course." 

She ran out of the room in fear as Romonus over the years had become very proud of his power. He disliked those who did not improve themselves and relied on others. Like the maid who ran out as she got some status by sucking off his Father now and then. 

'Honestly, Dad is a lucky guy. Hundreds of women are all for him and no one can tell him that is wrong. Then again, he is effectively a king as a Clan Lord. Can't be me though.' 

If and when he got his harem, he did not want a bunch of weaklings. He wanted women to have some significance instead of dime-a-dozen maids like his Fathers. Sure, they were hot, but he was sure if he asked they would fuck him in a heartbeat. 

They were after status, not love. While he was after power. He had not forgotten why he was here. He was here to change the cannon and make a nuisance of himself. He had 7 more years until he was 18 when the cannon started. 

He felt he had prepared enough and it was time for him to begin to cause the chaos he had promised. He grabbed his sword and placed it into his Spatial Ring. He was going to not bring it this time around for his Mother's sake. 

He waved his hands and instantly removed his outfit which he placed onto a mannequin to hold it. He then placed a hand on his chest and dense Demonic Energy began to flow over his body which he quickly formed into a fancy suit. 

(Image here)

He modeled it after John Wick's suit as it was a classic and one he quite liked. He quickly looked himself in the mirror and smiled as he had become a good-looking guy. Sure he was only 11, but the next 4 years were changing him greatly.