After the incident in the shower, Chojusen separated from Asia and went back to training in his room. His Magic Body Refining made his physical power increase exponentially. The fact that he had a Holy Yin Rebirth to replenish his hastily spent magic energy, made the rate of progression all the more exaggerated.
The increase was so exaggerated, that Chojusen spent half his time that night training his cloning skill to make more clones and he still managed to increase his power stat more than the previous nights. As he trained, he felt an itch coming from his arm and it started to concern him, so he stopped his training in tried to investigate.
He looked at his arm and scanned it with his energy, but nothing changed; if anything the itching got worse. The system saw Chojusen's predicament and as his savior, gave him some words of advice.
[Hey, remember that you now have a living skill; Boosted Gear. What you're looking for is probably related to that. The only reason Ddraig can't contact you directly is because your will is close to his level while in that soul form.]
"Ok? So how do I contact him? This itching is really annoying..."
[Activate the Boosted Gear.]
Chojusen followed through with the system's suggestion and upon summoning his Boosted Gear, he was met with the pitiful screaming and yelling of a broken man; it sounded less like a dragon and more like a prisoner of war.
"You! What did you do to me?" These were the words Chojusen could make out of the dragons sobbing and crying noises.
"Huh? What did I do to you?"
"Don't play dumb! My perfect red scales… they're gone! And now I have this sickly grey color and these weird gold runes in my green crystals of power… What did I do to deserve this!?"
"You're mad that I made you even stronger?"
"Stronger? I was once a Heavenly Dragon Emperor! What could possible have added to make me stronger?!"
"I made you a Chaosfiend..."
"Chaosfien… WHAT! Those are impossible to "make." Besides, that's obviously not true as I still can't sense Chao…" Ddraig suddenly understood what all the grey mist that covered his domain was. He said "You really made me a Chaosfiend!"
"Are you still mad?"
"... A little… Now everyone who knew of me will laugh when they see that my red scales turned grey..."
"It's a small price to pay to become a Chaosfiend. If they really laugh at you, it'll be out of jealousy."
…
After that interruption from Ddraig, Chojusen spent the rest of that night training away. The next day, he told Asia to come to school with him, after he made her a set girl's uniform. Once he got to school, Chojusen could use his teleportation sensing range to find Rias. When he found her, she was taking another bath…
Chojusen asked her if she could pull some strings to add Asia to the school as a transfer student. Chojusen asking for a favor on her behalf made Rias interested in who this new girl was so she probed her energy; a decision she regretted almost immediately.
Asia was just recently reincarnated as a Chaosfiend, so her bloodline was not exactly stable. Right now, the probing of a mere devil was like the worst insult to her Chaosfiend blood. This caused Asia to go completely unconscious and a new persona took over momentarily.
Asia, now covered in grey-golden tattoos and emanating the pressure of grandmist, coldly said "Probing me?"
Chojusen had to grab her hand to calm her down. He faced Rias and said "Sorry, she's still new to the whole reincarnating thing. Oh, and here are your pawn pieces."
"???" Rias didn't know which question to ask first. Reincarnating thing? You mean you reincarnated her? Here are my pawn pieces back? How did you even take them out of your body? Those are directly connected to the soul...
The only thing Rias could say right away was "I… I can fit her into your class. Just give me a second..."
"Thanks~"
"Issei… You giving me back my pawn pieces… are you leaving my side?"
"What? No of course not."
Rias would cry tears of joy if she didn't have some subconscious pride keeping her from doing it. She said "You mean it?"
"Of course. I deadly serious. You guys are the only devils I know of. Where else would I get all this free training and sparring?"
Chojusen had a way to flip people's moods through just a couple sentences and for the first time, his words made someone heartbroken after giving them hope. Rias said "Training huh? I guess that's all we're good for..."
"Don't feel so down. Remember I recently had my memories erased. What kind of special relationship doesn't take time to develop?"
Rias felt a bit better after hearing Chojusen try to cheer her up. She said "Anyways, I don't know what kind of being you made her, but since she's clearly got access to demonic energy. I guess she's also one of us. I'll make sure to include her in our trip to the Pet Dimension."
As Rias said this, a group of student council members entered the room. The president of the student council said "You plan on taking the trip to the Pet Dimension this month?"
Rias said "Sona! Yes, I have… two members that need familiars."
"Well, it seems like we have conflicting interests… How do you want to settle this."
"We do it the old fashion way..."
Then both said "A match of tennis."
…
Chojusen helped accommodate Asia into his classroom after she was properly registered in the school and the rest of the school day continued on like normal. The only thing that changed was that now, Chojusen would only give his cooking to Asia in Home Economics and he would be training her in Physical Education.
After school, Chojusen planned on discussing more magic energy related things with Akeno, but he noticed that all the members of the Occult Research Club where out on the field watching their president — Rias — battle against the enemy president of the student council — Sona. Chojusen wouldn't lose much time by watching the game of tennis, so he made his way to the tennis courts.
The two girls overdid it in Chojusen's opinion… They started the match normally, but then quickly escalated the tennis match to include magic energy. Every hit of the tennis ball would either curve at impossible angles after hitting the floor or travel at supersonic speeds. The only reason no one threw odd looks at Rias or Sona was because they used magic to make the tennis match look relatively normal.
Chojusen didn't understand tennis as he lost interest in sports after the baseball incident, so he had no idea why the tennis match ended as void. With the tennis match being inconclusive of who gets to go to the Pet Dimension, it was decided that a dodgeball game tomorrow night would be the deciding factor.
Akeno had to explain to Chojusen what dodgeball was after staring at his questioning glare for the better half of an hour. After leaving school and going home, Chojusen thought he would have a normal night of training, but he had a visitor. Asia knocked on his bedroom door and Chojusen invited her in.
She told Chojusen that she wanted to make headbands to boost their team's morale for tomorrow and after explaining why the head bands were so important, Chojusen used Armament Creation to create professional looking headbands for her.
The next day, after school, Chojusen and Asia met with Rias and her peerage in the school gymnasium. Asia handed everyone out the headbands and received praise from everyone for being so considerate. However, when she told everyone that it was Chojusen who made the headbands, they all looked at him in a new light.
Eventually, the student council devils made it to the gymnasium and the dodgeball match started. For the first couple minutes, Chojusen just watched in awe at how silly all the people in this match behaved. He couldn't believe that they would bring normal gym clothes that offered no extra protection, in a match of magical dodgeball.
Every time the ball grazed someone, their clothes would be eviscerated. Even catching the ball would be futile as the remnants of the magic infused, would just cut up the clothes of everyone to a worse extent. By the time people started targeting Chojusen, almost all the people had suffered at the hands of the clothes-cutting dodgeball.
Chojusen's clothes were naturally not affected by the dodgeball as his clothes were created with Armament Creation and only Emperor Class Devils could hope to cut up his clothes. When half the people on either side of the field were eliminated the student council started targeting Chojusen and succeeded in losing people at a faster rate.
Chojusen couldn't be bothered to attack the student council group as he felt bad for their already haggard appearance. Thus he only caught the dodgeballs coming his way and tossed them to Rias or the members of her peerage. His god-like handling of the dodgeball made him a serious threat to the enemy team, so Chojusen became target No. 1.
Making him their target only accelerated the rate that they lost players though, as even the magic infused dodgeball attacks that could create 10 meter wide craters should they land on the ground, where stopped effortlessly. Chojusen caught all the dodgeballs thrown his way, until the president of the student council got serious and threw a deadly attack his way.
For the student council president's attack, everyone watched with terror as they knew that perhaps only Rias could withstand such a formidable blow; they all prayed that Chojusen managed to cancel enough of the ball's power to not die instantly. However, to everyone's surprise, Chojusen tried to catch this ball like all the others; he was also somewhat serious as he had Density duplication on max.
In the end, he managed to catch the ball, but it exploded from the air inside collapsing. The shockwave from Chojusen catching the ball was so extreme that all the windows in the gymnasium exploded and the ground underneath him cracked with fissures for several meters.