Well. Seeing as how my friend forgot to add this when I told him to neither Mjgrazi17 or I, War Historian, own High school DxD. I, War Historian, do own Dani Thompson as she is my OC. Oh by the way, Rias will be referred to as the Scarlet Ruin Princess because her hair color is scarlet, not Crimson. The Gremory family doesn't have crimson hair. I know what crimson looks like, and it ain't crimson. BTW, the guest got what he/she wanted.

On with the story

Ten years later

"Issei, you're really showing your strength. Now comes your final test. Ace this and you will finally get your evil pieces. Serafall, let your feelings for your younger brother go as this requires the both of us to test him. Hold enough back that your mother doesn't kill us both for injuring her precious baby boy." Lord Sitri said. "Oh no. Mom killing me before having the lovey-lovey time with my brother and sister. If that happens, I'll tell mom you told me to." Serafall said.

"Damn it. I hate how you can throw anyone but your brother, sister, and mother under the bus. How do you even. Oh wait. One of the leaders of the Underworld." Lord Sitri said. "You know, if you're not going to test me, go to the library to talk. I've got things I've got to do. I've got a chess match against Sona, and a play date with Rias. I might not be spoiled but I hate impatience." Issei said.

"Well then son. Are we going to just sit around all day, or are we going to fight?" Lord Sitri asked.

At that moment, Issei launched himself at his father and half-sister. Due to prior knowledge, he knew that his sister was the more dangerous threat so he went after her first. "Sorry about this Serafall. Do know that I still love you and I hope you don't hold this above my head." Issei delivers a flame coated punch to his oldest sister, putting her out of action due to the sheer surprise. His father immediately saw what happened and was astonished at what his son was doing. His household was known for its prestigious control over water and, on occasion, ice. He's never seen a Sitri who could control fire as well as his son. Issei was literally wrapped in a protective case of fire.

As Issei wrapped himself in fire, he was manipulating the water to go after his father from behind while Issei flung fire at his father from the front. He's never seen a single devil have such great control of fire and water, be the person either a Sitri or Phenex. At this point, he saw a red glow start coming from his son' left arm.

"Alright Issei. Enough. You've gone over the expectations I set forth." Lord Sitri said. The spar was over. "By the way, I noticed a crimson glow coming from your left arm. I believe that it's a sacred gear and I want you to summon it." Lord Sitri said. "If I remember this right, imagine the strongest thing and mimic a pose of the being. Oh hell, this will be embarrassing." Issei said. "The person you imagine as the strongest being can't make you that embarrassed." Lord Sitri said reassuringly. "It's Serafall's favorite pose, so yes it is." Issei said causing his father to fall to the ground rolling every which way laughing. "Stop laughing old man. Unless you want me to wake HER up and tell her you were laughing at me." Issei's father then immediately shut up at the statement Issei said as there were three people he feared. Lisa, Sona and Serafall. In reverse order.

"I will vanquish all foes in Heaven and Earth." Issei chanted. He then did a pose that actually made Serafall, who had regained consciousness, gain a nosebleed which she then fainted from. After he finished, he felt more powerful than he was two minutes earlier. "No way. To think my son has this sacred gear. You are special my son. Really special." Lord Sitri said and motioned for him to stand next to his father.

"Son. You house the Boosted Gear, a mid-tier Longinus class sacred gear rumored to be strong enough to kill a god at full power. We need to start some new training so that you can unlock your balance breaker." Lord Sitri said.

Unknown Location

A woman was currently running with a ten year girl with silver hair.

" Hurry Valiana were almost in the Sitri territory once where there will be safe from your father " The woman said to her daughter, Valiana.

" Okay mom" Valiana said while crying softly.

But then just as they had made it to the road leading towards the Sitri mansion a hole appeared in the woman's stomach and soon she fell lifelessly to the ground with blood coming out of her mouth and soon another blast hit the woman's body destroying it completely.

" MOM" Valiana screamed in shock. Valiana angrily turned to face the person who killed her mother with tears coming down her face.

" Don't be sad my daughter you will be seeing your mother soon for I am about to do to you what I should have done years ago" A man with silver hair cruelly said.

However right before he could attack her his entire body was frozen solid.

" I'm assuming this must have been the devil we sensed" Lord Sitri said

" This is a naughty devil who I'm going to be glad to punish" Serafall said right before unleashing a decent amount of demonic energy at the frozen devil shattering him to pieces in the process.

Issei the walked up to Valiana and put a hand on her shoulder.

" Thank you" Valiana said while still crying.

" My name is Issei what's yours?"

" Valiana"

Lord Sitri then walked towards Issei and Valiana.

" There may be more enemies in the area we need to get back to the mansion you will be safe there" Lord Sitri said.

" Okay" Valiana said as Lord Sitri took out a special card used for creating a special magic circle that teleports beings to the sitri mansion.

Sitri Mansion

Once at the mansion Lord Sitri turned to Valiana.

" I know you have been through much but could you tell me why that man tried to kill you" Lord Sitri asked.

" That man was my father and he was trying to kill me because of this" after Valiana finished her sentence a pair of white dragon wings with eight energy "features" emerged from her back.

A/N: Hey readers someone asked what tba means so I figured I would let him or her know what it means. Tba means to be announced

A/N 2: Also I'm going to change the pieces a bit and I will release the harem either be the next chapter , chapter 4.

Peerage:

Mutated queen: Yasaka

Mutated rook : Valiana Lucifer

Rook: Rossweisse

Knight: Jeanne

Knight: Xenovia

Mutated Bishop: Kuroka

Bishop : Ravel

Mutated Pawn: Le Fay

Mutated Pawn: Lavina

Mutated Pawn: Dani Thompson

Mutated Pawn : Tba

Pawn: Kiyome Abe

Pawn: Elmenhilde

Pawn : Tba

Pawn TBa