Chapter 1: The Overwhelming Strength of One Man Inspires a Young Boy

A man that looked aged by battle smiled softly at the boy in the women's arms across from him and place his hand gently on the boys shoulder as his grey hair moved slightly in the soft breeze.

"Father?" The boy started with a curious gaze as he watched the grey haired man, his father look at him softly while remaining silent.

"You cheer your father on okay? Because today is when i will show you my strength, the strength i have in order to protect those i hold dear, a power you should inspire to have." The man told the young boy who gave a massive smile.

"Okay father i will" The boy answered as his father turn away from him and headed towards where a group of people were standing above a teleportation circle.

"Go kick her ass honey" The women holding the young boy cheered with a smile as the grey haired man raised his fist before he vanished from view along with the group of people.

"Come on Tatsuya, let's go watch your father" The women stated to the boy who nodded eagerly nodded his head. He had not seen his father fight before but from what his mother told him, he was so strong that he was undefeatable and that some people even renowned him as a monster but Tatsuya saw his father as the kind person that he was around him. He always gave him piggybacks even when he seemed to be angry at something.

The woman sat down on a nice leather couch with Tatsuya on her lap as she turned on the TV to the start of the rating game.

"Welcome ladies and gentlemen to the rating game that has been long awaited. Today Roygun Belphegor takes on 'The Emperor' Diehauser Belial for the the top spot of the rating game rankings. I am Grayfia Lucifuge, Queen of the current lucifer and i shall be presiding over this rating game. The rules for this rating game are simple, the victor will be the side who is the last one standing." Grayfia announced as the crowd around the stadium roared with excitement as the rating game field appeared. "The map chosen for this fight is an open field which each sides base being their designated castle. Now as each side is teleported in, let the game being"

Diehauser looked around at his peerage before he said words that shook the crowd.

"All of you, retire."

His peerage soon vanished from the battlefield as the announcement was made by Grayfia.

"All of Diehauser peerage...has retired" Grayfia announced as the crowd roared in confusion.

Tatsuya looked at the screen confused as he turned to women whose lap he was seated on.

"Mother, why has father….sent his friends away?" Tatsuya asked his mother who smiled and turned him to face the screen.

"Your father said he'd show you his strength, the strength he has in order to protect his loved ones, and that is exactly what he is going to do." His mother answered with a smile as she continued to watch as Diehauser made his way towards the opposition base with a grin on his face.

Roygun and her peerage approached Diehauser rapidly but found themselves stepping within a magical barrier.

Diehauser vanished from sight and quickly appeared in front of Royguns queen who tried to to conjure a defensive spell but failed to do so as Diehausers' fist collided with her stomach sending her flying.

"Don't try to block remember, he can just bypass your defense." Roygun reminded her peerage as she tried to fire her clans ability, which allowed her to manipulate the earth around her but found she was unable to.

"Wait...don't tell me that barrier…" She started but was interrupted by Diehauser who nodded before she could finish her sentence.

"This barrier that i created around me, makes everything in it worthless as long as i understand how it works of course." Diehauser confirmed as he looked around at Roygun and her peerage whose eyes were wide with disbelief and shock.

"Thats...thats absurd is there no limit…" A pawn of her peerage stated in shock as Diehauser turned towards them.

"There is a limit of course but a limit is only in place if you make it. No matter your background or abilities, you can be strong through hard work. Push past your limits and become strong. Now come at me and i shall fight you at my full strength or you may retire and never know if you can beat me" Diehauser announced and with a roar of frustration, Roygun and her peerage moved forward to face the crowned 'Emperor' of the underworld.

Tatsuya watched in awe as his father took down each foe before him with finesse and utmost skill as something stirred within him, a drive to be strong.

"Hey mother, could i be as strong as father?" Tatsuya asked his mother as he turned to face her.

"Of course my son, it is as your father said, anyone can be strong by continuously pushing past your limits." Tatsuya's mother informed her son who beamed with happiness as he turned back to the screen to see his father in the middle of a now desolate and destroyed field littered with craters and debri all around him.

"The Victor of the rating game is 'The Emperor' Diehauser Belial." Grayfia announced as the crowd went berserk with cheers and applause as Diehauser raised his fist toward the sky as he was teleported out of the arena.

-Later on-

Diehauser was laying down on the couch with a sleeping Tatsuya in his arms. He looked down at the brown haired boy with a smile. While he had inherited his mother's hair colour, his facial features he had inherited from him.

"You know what he said to me while watching you kick ass?" Tatsuya's mother asked him as she knelt down next to the couch and ran her hand softly through Tatsuya's hair. "He asked if he could be as strong as you. To think our boy is only 6 years old and he already wants to be stronger then his old man."

"Its good to have a goal like that, i know i certainly thought that when i was his age but i hope he can find his own way, and bring his abilities to new heights instead of trying to copy me but only time will tell i suppose" Diehauser stated as he kissed his wife on the forehead before taking Tatsuya up to his room.

He could not help but smile at the young boy in his arms. He had a feeling that this boy, his son, would be even stronger than him but as he told his wife, only time will tell.

A/N: Hello my beautiful and handsome readers, i hope you enjoyed reading 'Belial's Heir'. Now i know that Diehauser is probably different to how he was in cannon but it was hard to get his personality down from the little information there was on the wiki so i just wrote what i felt was write and i hope you guys and girls understand. Also Issei was originally the main character but it has been Change to an OC named Tatsuya
What do you guys think of this idea, with Tatsuya being the son of Diehauser Belial? Let me know in PM's or reviews and also leave suggestions or things you'd want to see in this story. Next chapter will be after a timeskip and will revel Tatsuya to the underworld, as at the moment in the story none of the pillars know about him apart from the Belial household.

I once again hope you guys enjoyed this chapter and will be sticking around for more as this story is far from over.