*Aiden's POV*
So the bastard decided to show himself....and he brought his bitches(and his sister) with him like some kinda pimp...
Aiden: Alright,that's enough Riser, you're gonna break your arm if you keep jerking yourself off that much.
Everyone including him look at me.
Riser:One of Lord Sirzechs' rooks...?*he then looks at Sasha in a perverted way* And His Lordship's Bishop~....What a surprise.
Ravel:*What is Aiden doing here? Not that I mind...*
Before I could answer Grayfia interrupts me
Grayfia:He and Sasha were ordered by his Lordship to watch over Lady Rias.
Sasha:Correct,and His Lordship wouldn't appreciate you attempting to court her before the wedding,considering it is out of obligation rather than love.
Riser gets an annoyed look
Riser:You may be of Lord Sirzechs' peerage, but you must still be respectful to other Families,including Riser's.
Aiden:Oh we're respectful,the reason we're not to you is cause you're a shameless fuckboy. I say this with a smug look on my face
This causes everyone to look at me with shock, even Grayfia.
Aiden:Got nothing to say Riser? Don't act so surprised. With your shitty attitude, it was only a matter of time for someone to tell you that to your face.Now scram before I clip your wings. I say while cracking my knuckles and releasing some of my monstrous aura while giving him a bloodthirsty smirk. I start walking up to him with killer intent until his Queen(and possibly his Top Bitch) tries to shoot some lightning at me.
Yubelluna: You will not lay a hand on Lord Riser!
But I raise my right hand at the lightning,pointing my index and middle finger at it catching it like a lightning rod, then redirecting it out the other hand and firing it right back at her,knocking her back several meters and on the ground. This leaves, Riser and Rias, aswell as their peerages in shock of how I quickly knocked her off her feet.
(Author'sNote: Anyone who gets this reference,Let me know in the comment section and hats off to you.)
Grayfia:That's far enough Aiden!
Aiden:Hmph...
Grayfia: As you have seen, Aiden is quite skilled and aggressive when it comes to battle. Which is why Lord Riser, you and four of peerage members of your choosing, will face him in battle after you defeat Lady Rias in the Rating Game. Sirzechs states it is one final test to see if you are worthy of having His Lordship's sister as your wife.
Riser:*Gets a frustrated look on his face* I see....very well, then I propose the rating game to begin in 10 days, that should be enough time for Lady Rias' peerage to train...
And so it went.
While Sasha trained Asia, Akeno and Rias, I was gonna train Kiba, Koneko and....*sigh*...Issei....
*Third Person POV*
Asia: Miss Sasha? I've been meaning to ask...
Sasha: What is it Asia?
Asia: Will your training actually make us strong enough to win the rating game...?
Sasha: Well...maybe, but... then again, you guys losing means Aiden has the chance humiliate and brutalize Riser and get off Scott free,*looks at Rias* So in other words, you won't have to marry Riser at all.*she says with a smile*
Akeno: Huh, if Aiden is that strong, then why're we training if he can beat them so easily?
They're then interrupted by Issei who flies past them, crashing into a tree and sees Aiden walking up to them.
Aiden:Because we're not going to fight your battles for you, we're here to make you guys strong enough to give you a fighting chance against that bird brain.
Aiden:If you guys lose, then at least you gave it your all and put up one hell of a fight,then I'll gladly take the win for you guys.
By the end of the ten days, the results of their training were somewhat fruitful, and it was seemingly a close match, but eventually, even with Issei's stubbornness, they lost......
*Brief Timeskip*
Sasha:*Puts a hand on Rias' shoulder* You fought well, *Looks at the rest of her peerage* as did the rest of you. But now.....*She grows a smile* It's Aiden's turn.....
*Issei soon grows a smirk*
Issei: That bird brain doesn't have a chance against him! He's like a bulldozer mixed with a grizzly bear!
*Sasha chuckles at his behavior*
Asia: Is Aiden really strong enough to beat 5 people?*She soon remembers how he overkilled Freed*
Akeno:Well he IS the wielder of the Atomic Gear.....
*Soon, Aiden starts walking down to the stadium until he's met by Milicas*
Milicas: Uncle Aiden!
Aiden:*Grows a smile* Hey squirt. *Ruffles his hair* Gonna watch me fight?
Milicas: Yeah!....Are you gonna be able to beat that Riser guy....cause he looks like he heals really fast.....
Aiden: Oh don't worry about that, I'm gonna hurt him so bad, he won't be able to heal the damage I do to him.*smirks* Besides, this just means I don't have to hold back.
Milicas: Wow! You're awesome Uncle Aiden!
Aiden: You bet I am.*ruffles his hair and he runs off to sit with his Mother and Father.
*Everyone took their seats, including a Sirzechs bearing a small smirk on his face*
Grafya: You're smirking My love...
Sirzechs: Sorry dear, it's just I'm more or less excited to see this battle.
Grafya: And by that you mean "I want to see that vulgar buffoon Riser Phoenix finally get the beating he's had coming for the past several centuries by none other then my Mutated Rook who'll gladly fix the mistake I made" Does that sound right?
Sirzechs:........{Damn...she read me like a book...}
*On to the battle*
Riser: I'm afraid you won't be tasting victory, even if you are one of Sirzechs Rooks. In fact, after I win and take Rias, I might request Lord Sirzechs to have his newest Bishop to my peerage~.*he says smugly*(Author'sNote: It was at this moment, that Riser had severely fucked up)
Aiden:.........Y'know,I was just gonna knock you around and teach you some humility but no, now.........

......I'm gonna tear you apart....over and over again....Until you beg me to put you out of your misery.......*He Crosses his arms in front of him and activates his sacred gear* Atomic Gear....activate Balance Breaker.....Resurgence Protocol...

[There should be a GIF or video here. Update the app now to see it.]

He enters his balance breaker, but the blue flames become an ominous violet and gives off a sinister aura....

And Meanwhile, everyone who saw his transformation had their eyes widen greatly
Lord Phoenix: W-What sort of power is that...?!?!
Sirzechs: You see Lord Phoenix....Aiden Yamoshi...is the wielder of the Atomic Gear, which holds the power of the Titan King Godzilla.......
Lord and Lady Phoenix Soon turn pale upon hearing the dreaded titan's name, and even the Leviathan family who had also come to witness the fight had been shocked from this revelation....
Serafall: So he's this generation's King of Monsters........!!!
Sasha: And he's in his Resurgence form, a more powerful and aggressive version of his Balance Breaker, the fact that he immediately turned into that form only implies that Riser had said something to severely anger Aiden....and nobody wants to be on the receiving end of that rage....
Meanwhile with Riser, Ravel, Yubellina, and his 2 knights and Rook, are in utterly shocked and intimidated by this power and new appearance Aiden is showing.
Aiden: I'm gonna tell you girls something, you 4 stand aside and let me fight your precious Chicken shit leader, and I won't hurt any of you....
Riser:*Hides his nervousness* Y-You think you scare I?! THE GREAT RISER?!?! YOU ARE NOTHING COMPARED TO ME!!! KILL HIM!!!
His two knights charge at him only for him to grab their blades and break them in half, and they attempt to attack him bear handed.

Unfortunately they fail, miserably, and are no longer able to fight.
Issei: Holy shit.....!!!!
Sasha: Yep....
Rias: To think he was this powerful....!!!
Sasha: Uh-huh......
Riser:*looks to his Rook* Don't just stand there! Attack him!
She Charges at him and tries to hit him  but he out maneuvers her and hits her with an Atomic Shot.

Aiden: Don't say I didn't give you a chance to stay out of my way.....
Ravel sees this effortless and brutal display of power and falls off her feet and crawls back a bit in fear, Aiden merely looks at her for a second and then looks to Riser
Aiden: Looks like it's just you and me now......Hehehehe......perfect....

Aiden charges ferociously at Riser who attempts to hit him with a fire attack

But Aiden plows through the attack and punches Riser through a wall

Riser jumps back a bit and keeps trying to hit Aiden with a barrage of flames

But he remains unaffected and beats Riser down mercilessly

Everyone(except for Rias and Sirzechs along with their peerages) is shocked and intimidated and how brutally and effortlessly Aiden is beating Riser.
Riser:Tries to get up and barely manages to stay on his feet as his hideously disfigured body regenerates Y-You....T-Think you've won?!?! I am a Phoenix!!!! I cannot be defeated!!!!
He focuses all his power into a single shot and fires a burning blast point blank at Aiden....

Only for him to emerge with only a few scratches on his armor

Aiden:....Not too bad....but that was all you had right? Well then....
He grabs Riser's leg

And punches him so hard in the balls his GRANDKIDS are gonna be born with black eyes if Riser would be able to reproduce at all after this. This immediately makes every male audience member hold their crotches and wince at that painful sight.
Aiden: Now for the cherry on top....
He charges up a purple ball of energy and fires it at Riser, causing a massive explosion

Riser is soon seen, unconscious, and covered in injuries while only having his underwear being the only clothes he's still wearing.
Aiden: Well....that was fun. Now to end him....
But then Ravel runs up to him
Ravel: P-Please Sir Aiden! Have mercy on my brother! You've already won! She begged with a teary eyed expression, Soon, Aiden merely sighs and drops out of his Resurgence Balance Breaker.
Aiden: Fine. But keep a close eye on him...
Ravel: Y-Yes...O-Of course....
Aiden: And Ravel...?
Ravel: Y-Yes...?
Aiden: Sorry I scared you like that....but your prick of an older brother had it coming. He gently puts her on her feet See ya. He walks off
Ravel:*Blushes a bit* F-Farewell...

In the end, Rias no longer had to marry Riser, and Riser had gotten the comeuppance he deserved.

(Author'sNote: Looks like Ravel's gonna be in his harem aswell. :3 )