3rd. Pov.

Currently the victory party is being held in the Phenex territory. Different Nobles from different families are attending. Ravel was talking with some of them while playing her part as a the bratty little sister. Rias' peerage was upset that they let there king down and lost the Rating Gaming.

Koneko: I still can't believe it.

Kiba: Hey we did our best. I'm sure we'll find some way to get her out of this.

Akeno: Kiba's right. We just need an opportunity.

Soon Riser appeared in front of everyone wearing a fancy suit.

Riser: Riser would like to welcome all of you to Risers' wedding party.

Rias soon descended in a beautiful white dress and stood next to Riser with a sad look on her face. Soon after a loud commotion could be heard from outside the room. Soon the doors burst open and Issei is seen running in.

Issei: Rias Gremorys' virginity is mine to claim.

Sirzechs smirked at this and started to walk forward.

Riser: What is the meaning of this!? Riser demands an explanation.

Sirzechs: I can explain.

Riser: Lord Lucifer?

Sirzechs: I was quite disappointed in the match between you and my sister was, less then impressive. With you being a prestigious competitor and my sister, who had no experience what so ever. I thought we could make this interesting by putting two power houses against each other. A dragon against a phoenix. Truly an amazing match wouldn't you agree?

Riser: Hm. Yes that does sound interesting indeed.

Sirzechs: I'm glad that you agree.

Riser: However it would hardly be a challenge.

Sirzechs was caught off guard by this. He wasn't expecting Riser to not take the challenge.

Sirzechs: What do you mean?

Riser: A dragon and a phoenix is an interesting batting, but could you truly call that a fight? An imortal fire bird, against a beast of absolute power. Riser expected something like this himself, so I propose a different form of entertainment.

Sizechs: Are you certain?

Riser: Are you doubting Risers' judgment Lord Lucifer? I simply wish for everyone to enjoy this little, "show."

Sirzechs: No. It's just, I can't think of something better.

Issei: Ha! So you're nothing more than a coward!

Riser: HAHAHAHA! That is the last thing Riser is. Riser just feels sorry for you that's all. And having better entertainment is always welcomed. Tell you what. Riser will make a deal with you. If Risers' friend beats you, he gets to marry Rias, but if you beat him she can leave.

Issei: Deal!

Riser then made a magic circle and summoned Y/N who was currently in a jacket with a cap pulled down to cover his face. 

(Looks like this, but without the gauntlets)

Riser smirked and started egging on Sirzechs who eventually gave in to the the deal. Issei and Y/N were then transported into a false reality similar to that during the rating game.

Issei: I'm taking Rias back!

Y/N: ....

Issei: Riser will pay for what he's done! And so will you!

Y/N: .....

Issei: Hey! I'm talking to you!

Y/N?: 206.

Issei: Huh?

Y/N?: That's how many bones are in the average human body. A devil has the same amount. 206 bones.

Issei: What does that have to do with-

Y/N: I wonder how many of them I'll break before you lose? Only one way to find out.

Issei boosted and a red armor covered his body except for his head. Y/N however, who was acting strange, kept his hands in his pockets and stood before Issei.

Grayfia: Let the fight... Begin!

Issei charged towards Y/N. He reeled his fist back and threw a punch at him with all of his might.

*Boom*

Issei's punch connected with Y/N's face. A large gust of wind kicked up. After a few minutes the dust settled and Sirzechs was at ease since he didn't sense any of Y/N's power. Issei however didn't move and saw two glowing red eyes staring directly at him. Eventually, Y/N lifted his arm and threw a punch at Issei's face which sent him back. Y/N then pulled his cap down, making sure that it covered his face. Issei was tumbling back until his back hit a wall. Y/N was slowly walking towards him with his hands back into his coat pockets. Everyone was surprised to see Y/N without a scratch on him and he managed to punch away the red dragon emperor in a single hit. Issei slowly got up and boosted again

Ddraig: Boost! Boost! Boost! Boost! Boost! Boost! Boost! Boost!

Issei: Dragon Shot!!!

Issei fired a red beam of energy at Y/n who was still walking towards him. Y/n then lifted his hand towards the beam. As the beam made contact with Y/N's hand there was a massive explosion that pushed Y/N back. While Rias and Sirzechs had smiles  on their faces, Riser smirked. You see Y/N used one of his Sacred Gears' abilities. He's able to produce a corrosive slime that can explode after a set amount or from a powerful heat. Y/N coated his palm in in said slime which exploded after it hit the dragon shot. What everyone didn't know was that his secondary effect kicked in. While Y/N was pushed back he did absorb the kinetic energy. Which he can store and release it in a single attack. back to the fight Y/N gets up and dusts himself off. He looks at issei who's currently kneeling on the ground and panting.

Issei: How are you still standing? I put everything into that attack!

Y/N: If that's your all, then you are by far the weakest person I have ever fought. Here. Let me show you how it's done.

Y/N then pointed his palm towards Issei. A ball of green energy began to from from Y/N's palm. It kept getting bigger and bigger. Once it got to its maximum size Y/N made a gripping motion with his hand and the ball began to slowly shrink until it fit in the palm of his hand.

Y/N: Dragon Killer.

Y/N launched the ball in front of him and punched it with his other hand sending a giant green beam towards Issei until-

*Boom*

It made contact and a giant explosion was created upon contact. The ground was burnt from the blast leaving a trail from the source. After the dust cleared and Issei is seen lying down unconscious.

Grayfia: Issei is currently unconscious. Risers' representative has-

Issei: Wait!

Issei was slowly getting up as he had his gauntlet still on his arm.

Issei: I'm not done yet.

Drraig: Boost!

Issei: I can't lose.

Ddraig: Boost!

Issei: I won't lose!

Ddraig: Boost!

Issei's power then skyrocketed after only three boosts from his Boosted Gear. Y/N however was surprised by this development.

Y/N: What the hell?

Brachy: Careful kid. Something's wrong. Ddraig is still asleep, but the kid tapped into his power.

Y/N: Is that even possible?

Brachy: It shouldn't be, Unless he gave up a part of himself to Ddraig.

Y/N: Well, looks like things a starting to get interesting.

Ddraig: Eruption!!!

Issei lunged at Y/n at blinding speed, throwing a punch at him, But Y/N quickly put his arms up and blocked the punch, but the force was so strong, Issei was pushing him back. They kept going until Y/N's back hit the wall. Issei had A face of pure rage while Y/N was just smirking. Y/N started to lean forward until he pushed Issei away and dashed after him. Y/N Started throwing jabs at Issei's face. Issei threw a straight punch which was countered be a punch thrown by Y/N. The two of them started trading attacks from punches to kicks. The attacks kept going and neither one of them backed down, but the difference in their strength was so large that it was visible. Issei was starting to be affected. His punches started to get slower and slower until he couldn't throw a single one and he was just getting bombarded by countless attacks. After a while he stopped moving. Y/N stopped his onslaught and saw Issei just standing there. He slowly fell back, but Y/N caught him by his shirt. Issei was beaten and bloody, barely clinging to what little life he had. Y/N however hardly had a single scratch on him.

Grayfia: Issei is currently incapable of continuing. The winner is the representative of Riser Phenex.

After her announcement, Grayfia teleported both Y/N and Issei back to the party

Riser: I hope that was entertaining enough for you lord Sirzechs?

Sirzechs grit his teeth and looked down knowing that his plan to save his sister from the arranged marriage was a complete and utter failure.

Sirzechs: Yes. That fight was most surprising to all of us.

Riser: Then I hope you will uphold your end of the bargain?

Sirzechs: Yes. Rias will no longer marry you, but instead your representative.

Y/N, who's identity was still a mystery to everyone except Riser and those from his peerage and family looked to Riser who only smiled and nodded to him. Y/N walked towards Rias who was tending to Issei. He kneeled down and leaned into her ear and whispered-

Y/N: Don't make any sudden movements. When Issei is all better bring your peerage to my house. I'll explain the rest there.

With that he got up and walked back over to Riser and waited to be teleported back home.

Riser: I apologize everyone for wasting your time. However I do hope that little skirmish was entertaining enough for some of you.

Noble: Who exactly is that human Lord Riser?

Noble2: Yes. I would love to add him to my peerage.

Riser: All you need to know is this. If you do try to add him to you peerage or go after anyone he may care about you may end up dead. Make no mistake, that is not a threat from me. He se is simply to strong for you.

Many of the other devils were taken back by his statement, but decided not to say anything that might upset Y/N.

Riser: Thank you my friend for that wonderful show. Until we meet again.

Y/N nodded and was then teleported back to his home.

Y/N: Phew. Well that happened.

Brachy: The plan worked and that's all that matters

Y/N: I guess. I just feel bad that Rias has to suffer so much in order for us to proceed.

Brachy: Don't worry. She won't suffer for much longer.

Timeskip

Y/N along with Riser and his peerage are seen sitting in the living room.

Ravel: How much longer do we have to wait?

Riser: Indeed. Are you sure they'll show up Y/N?

Y/N: Yeah. They should be here right about-

*Ding Dong*

Y/N: Now.

Y/N got up and went to the door where Rias and her peerage were standing glaring daggers at him.

Rias: You have a lot of explaining to do.

Y/N: All will be revealed. Come on in.

When they entered they saw Riser and his peerage.

Rias: What are they doing here?

Y/N: They're with me now calm down.

Rias sat down and her peerage stood behind her.

Rias: What is it? Why did you do it?

Y/N: Well to simplify all of the information I plan on telling you,-

I have reason to believe that your brother is going to start another war with the power of an elder dragon. No big deal.

A/N: Tell me what you think.