As Chojusen's beam reached the peak of perfection and he reached out his hand to fuel the beam and erase Riser from existence, Riser's little sister — his bishop piece — stood before him and cried out "Stop! You've already won the game. Don't kill him."
Chojusen wasn't in his right mind, so he said "Little girl, get the fuck out of my way or I'll just have to take you with me!" Miraculously, the dumb blond actually misinterpreted his obvious threat as a sign of flirting; she thought "take you with me" was an invitation to a date.
Her thoughtless blushing and acting like a cutesy girl, completely ruined the serious atmosphere. And just as Chojusen was about to double teleport to get the girl out of his way, Sona's voice echoed through the air "Riser, forfeits. Rias wins."
Before Chojusen — or anyone for that matter — could do anything, everyone within the Game Field was teleported out. Chojusen in his transformed and seething state appeared next to Asia, Rias and her peerage. He only calmed down when Rias hugged him from behind and said "You can stop now. We already won..." Seeing how angry and concerned he was by Riser's threats, made Rias feel a spark of love in her heart.
Chojusen slowly withdrew his aura and cancelled his Nephilim True Body Form. He was still a bit annoyed about Riser, but knowing that Rias won the match cured his sour mood. Grayfia had specifically stated that Rias would get her wish if she beat Riser, so he knew that her arranged marriage was no longer an issue.
By the time the Rating Game finished, it was night time, so the various members of the Occult Research Club split up to go back home. Before leaving though, Akeno pulled Chojusen off to the side and asked if she could now live together with him; if she couldn't live at his house, there shouldn't be a problem living in his personal dimension.
Chojusen didn't really need to think for this sort of question; obviously she could live with him. Thus, that night, Chojusen, Asia, and Akeno walked back to Chojusen's house. After explaining the situation to his parents, Chojusen started to think there was something wrong with them, as they did absolutely nothing to stop yet another gorgeous beauty from living under the same roof as him.
That night, Akeno did her best to get Chojusen to stop thinking about Rias; she knew that Chojusen would eventually have Rias and many more, but seeing him in such a bad mood broke her heart. But their "extracurricular activities" were stopped when a gray teleportation seal manifested on Chojusen's room.
Chojusen and Akeno quickly got dressed before Grayfia's teleportation finished. She was stunned to see Akeno in Chojusen's room so late at night, but there was a pressing matter on hand, so she didn't become distracted. Grayfia said "Sorry for intruding… But your precious president has been kidnapped and forced to go through her engagement party tonight."
"Oh? Would you mind running that back once more?"
"Rias has been forced to undergo her engagement party tonight."
"Well, Seeing that you came all this way to tell me, I guess you want me to do something about that. Right?" Chojusen was trying really hard to not go into another fit of rage.
"That's right. Quite perceptive of you… Rias' brother, has sent me here to give you a teleportation seal to steal her back. He's grown… fond of you, after that wonderful display you put on during the Rating Game."
"Her brother? I guess I'll have to repay the favor some other time."
Chojusen took the teleportation seal out of Grayfia's hand and teleported himself to the Underworld.
…
Somewhere in the Phoenix territory in the Underworld, Riser was dressed in white tuxedo giving a toast to all the high ranking devils that made it to his hastily assembled engagement party. After his terrible display in the Rating Game against Rias, his reputation had taken a dive, and now that his father threw a tantrum demanding that the head of the Gremory Clan abide by their agreement and marry Rias to his son, his reputation was at an all time low.
The only reason the Gremory Clan head agreed, was because of the scheming of his son, who had planned something for Chojusen once he crashed the party.
Chojusen wasted no time breaking into the party and gathering all the attention after he completed his teleportation. His teleportation range had long since reached the level where he could go millions of kilometers in one go, so he directly teleported in front of Riser after reaching the underworld.
With Riser right next to his face, Chojusen had eyes that spelled the former's death. Chojusen said "Was the beating I gave you earlier not enough?" Before things got out of hand, Sirzechs — Rias' brother — teleported in front of Chojusen, while Riser's father teleported in front of him.
Lord Phoenix — Riser's father— said "Shitty kid, fuck off from this party! You weren't invited."
Sirzech, with a smile on his face, said "Now, now Lord Phoenix. Did we not have an agreement to cancel out the marriage if your son lost to my sister in a Rating Game."
"Watch you mouth! You may be a Satan and a Lucifer, but MY agreements with your father still hold true."
Sirzechs momentarily released an ounce of his Satan Source, he said "What was that?" The pressure from his body made everyone shed a layer of sweat, but the Phoenix was not willing to back down. Sirzechs withdrew his Satan Source and said "How about we settle this with a rematch between Riser and my friend over here?" He pointed at Chojusen.
Lord Phoenix thought about the offer and after making a pained face he agreed to the terms. But Sirzech said "Since this is a rematch with Riser's prize being Rias, should he win. I think you should offer something of the same value for our little friend Chojusen over here." Lord Phoenix didn't doubt his calculations, he firmly believed that Riser would win with a little extra help. Thus he declared that Ravel — his daughter, and bishop piece to Riser — would be transferred to Chojusen if he won.
As Sirzechs had someone prepare a field for Chojusen and Riser to fight in, Lord Phoenix gave his son a small bottle and told him to not hesitate to use it before the match started.
Chojusen didn't care what Riser was given; nothing could possibly make Riser breakthrough three of power levels, required to match Chojusen's peak.
When the arena was completely constructed, Chojusen and Riser teleported over to start their fight. Chojusen made no effort to stop Riser from consuming whatever was in the bottle his father gave him. But Riser, didn't take any chances and directly drank the contents of the bottle before the start of the fight was announced.
As soon as the bottle was emptied, Riser was consumed in a blazing fire and body was coated with a reddish-orange immortal flame. His power grew to dozens of times stronger than his previous peak when the start of the match was called. Riser blasted himself towards Chojusen as soon as the match started, leaving behind a deep hole where he once stood.
To match Riser's speed, Chojusen used a holy lightning coating as well as a gravity boost. To match his strength, density duplication and the lightning coating on his heavenly staff where more than enough.
The two then started a grand battle shaking the entire stadium and Underworld for hundreds of kilometers with each clash. However, whatever Riser took kept increasing his strength, and soon his ever increasing strength reached the maximum Chojusen could fend off in his base form. When Riser managed to get a solid punch on Chojusen, sending him crashing through the entire arena, Chojusen decided to transform into his Nephilim True Form and the tides turn in his favor once more.
However, after a couple more minutes, Riser's still increasing strength put him ahead of Chojusen once more. When it finally stopped increasing, Riser was at the peak of strength possible for Emperor Class Devils.
Chojusen decided to end the match when he found the limit to Riser's strength by using his Boosted Gear for the first time. He summoned the Sacred Gear to his arm and charged it up for half a minute before getting his powers multiplied by eight times. Now, eight times stronger, Chojusen teleported over to Riser and knocked him down to what was left of the arena.
To finish him off, Chojusen charged up a holy supernova and destroyed all traces of Riser's existence; he also inadvertently destroyed the arena and everything for dozens of kilometers. If he weren't a complete immortal the story would end there, alas he had complete immortality and even from the dust, his body reformed completely. Being completely extinguished by a holy flame wouldn't kill Riser, but it would consume a big chunk of his near endless lifespan as well as bring him one of the worst pains imaginable.
Chojusen didn't want to continue launching Supernovas and Beams at Riser, so instead, he created a Five Layered Immortal Flame Seal in his hands and imprinted it on Riser's body after a quick teleportation. This was one of the many seals Chojusen learned how to make from studying the seals of the Omniseal Unlock and its effects were to keep an inextinguishable flame within the targets body until they either died or the person who casted the seal erased it.
Chojusen chose to seal an Immortal Holy Flame within Riser's body and he would keep it active for minutes on end until Riser chose to forfeit the match. It didn't take long, as Riser appeared to have taken a massive backlash from consuming whatever it was that his father gave him. Unfortunately, the seal was active when the backlash came, so Riser squealed like pig being slaughtered, until Chojusen deactivated it and he was finally able to utter words of defeat; he directly collapsed after forfeiting the match.