I do not own High school DxD.

This is another OC. This one was however requested by 3e. Most of it comes from him with me only making some adjustments.

Story Name: Gremory´s Black Dragon King

name: William Brune (Gremory)

Also known as: subject #37 (by the Naberius Clan), Black Dragon (shared with Vritra), Black Dragon King (shared with Vritra), Prison King (shared with Vritra), Gremory´s Dragon King, Strongest Dragon King, Dragon King of Darkness and Destruction

Age: 17

Family: Rose Ambrosius Brune (mother), Sirzechs Lucifer (father), Grafiya Lucifuge (step-mother), Rias Gremory (aunt but acts more like a sister), Tiamat (blood-relative?, mother?), Merlin (distant ancestor)

Homeland: born in Switzerland but was mostly raised in the Underworld, currently lives in Kuoh Town Japan

Likes: animes and mangas especially shounen (also ecchi and hentai although he never admits and has no collections so Grafiya doesn´t destroy them), Japanese culture (Rias hooked him), training with Valencia or Tiamat, practice magic, go to meetings with his girls, eat sweets and delicious dishes

Dislikes: Naberius Clan, old devils who force him to marry people he doesn't want and try to interfere in his life, heirs trying to get the girls who like him, people who try to spy on them (perverted trio)

Appearance: Long red hair with purple streaks on the left side which is tied into a high ponytail. Heterochromatic eyes with the right eye similar to Sirzechs blue eyes and the left one dark blue with black pupil which he hides with an eye patch with the image of Tiamat's head on. He thinks it is a cool design. He is 1.89cm tall, pretty face kind of androgynous but not too much, as a child he looked a bit like a girl.

Powers: Power of Destruction (Beal Clan ability), Prediction (Gremory Clan ability), Dragon Taming skills, Devil, Darkness, Fire, Nordic magic, Senjutsu and Touki, Charm (Merlin's Innate Ability for being part Incubus).

Sacred Gear: All parts of Vritra

Balance Breaker: It is an black armor with blue and red marks and black and blues flames cover parts of it. The powers of Vritra are amplified and William is able to use Tiamat´s power in this form without deadly drawbacks.

Backstory:

His mother was Grafiya's hired magician. After a night where she, Sirzechs and Grafiya an extremely rare dwarf wine drank ended with Rose and Sirzechs sleeping together. Because of that the magical contract was canceled by Rose out of regrets and run away. Both Sirzechs and Grafiya did however not blame her. 9 months later William was born as the result of that night. Despised being the unwilling symbol of Rose´s "betrayal" against Grafiya she still loved her son.

William live with his mother was calm and quite. His mother taught him about the mystical side of the world, magic and upon awakening his Sacred Gear how to use it.

At 6 years old he and his mother were attacked by devils of the Naberius clan. In that attack his mother was killed and he was kidnapped. The goal was to make a weapon out of William. In order to that he was experimented on and was forced to take the other parts of Vritra. In the captivity he meet three girls: Kuroka, Shirone and Stella Vermillion (from Rakudai Kishi no Eiyuutan).

One of the experiments of the Naberius had them inject him with Tiamat´s blood. This gave him the power of Tiamat but the blood made him go crazy and activated his Balance Breaker.

Sirzechs and Grafiya having heard rumors that the Naberius Clan tried to create a super devil and use him or her as a weapon. So they came to investigate but what they saw was William destroying one of the Naberius laboratories. Only after he destroyed most of it were Kuroka, Shirone and Stella calm him down and release his Balance Breaker.

They were all taken to Serafall Leviathan Memorial Hospital where they discovered William´s lineage. Sirzechs massacred most of the Naberius clan and all those involved in his wrath upon hearing that. After which he took William in through William asked to keep Brune as his surname both to remember his mother and as to not create a conflict as to who becomes the next head of the Gremory Clan since he is the biological son of Sirzechs.

To insure that the experiments have no negative consequences Ajuka took him to his mansion to do special check-ups. There he met Tiamat who instantly notice her blood in William´s vein. Upon being explained his origin and story Tiamat decide to see him as family so she decided to become his familiar in order to be summoned if he needs her.

Sirzechs and William spend often all together after being released from the hospital. It was so much that William went with his father to some business meeting. One of them was a secret between Sirzechs, Azazel and Michael. On that meeting he meet Valencia (fem Vali). Both became friends and met many times. When they got their Evil Pieces both wanted the other to be their Queen. Neither wanted to give in so they decided that the stronger one would be the King and weaker one would be the Queen. So they fought. The end result was that William won and he became the King. The second and third person to recruit for his Peerage were Kuroka and Stella who asked him to become of it. After that he went travelling to find members for his Peerage.

On his travels William heard rumors of a member the Naberius Clan trying to create artificial devils which were mostly successful. While they were physical strong and most had no freewill or emotion they were lacking in magical power (especially those who lack emotions), cost a fortune to creat and had only a short lifespan of 1 year at most. William decided to destroy that member and his plan. He managed that and even turned the most successful of those artificial devil to his Rook (Zest from shimai maou).

Peerage:
Mutated Queen: Valencia
Mutated Rook: Bikou
Rook: Zest
Mutated Bishop: Kuroka
Bishop: Le fay Pendragon
Mutated Knight: Arthur Pendragon
Knight: Stella Vermillion (Sacred Gear:
Mutated pawn: Jeanne
Pawn: Elaine Westcott

I know I wanted to write here something but I do not remember... Oh well it can´t be that important then.

Anyways I wish you guys a good day.

Goodbye with my best regards.