3rf Person POV
It's night time and everyone already sleep tight on their own room, exhausted after doing training regime from Y/n. But, the young Astaroth haven't sleeping well as knowing the facts that dream will coming to haunt him.
Y/n sighed as pulling a phone from his pocket and dial a number.
???: "Yes, Master???"
Y/n: "I need Yagurou, Nanako, Ren and Ken for tomorrow morning. I expected them to arrived early in the morning... I'll send you the location"
???: "Why in rush, Y/n? Nanako and Yagurou hasn't in duty since you giving them days off!!!"
Y/n: "It's urgent business, i need them to train the Greymory... it's perfect chance to meeting up with Lucifer in the future"
???: "*Gaps* Did you meet her???"
Y/n: "Yes... I've meet your mother... indeed, she was beautiful like you"
???: "I see... Understood, I shall send them"
The phone call was cutted as Y/n back to his comfortable bed.
Y/n: "Did she ignored my perfect charming flirt?"
Absol: [Indeed, Y/n... She ignored you]
Y/n: "Shut up, Absol"
Y/n cut the mind link as he fall asleep, felling tired from training the Gremory.
(Timeskip brought to you by Sir. Hell bitch slapping Absol head as laughing like an maniac)
In the next morning where the Gremory household hasn't awake from their sleep, Y/n was already outside, crossing his arm while waiting his peerage members and closing his eyes.
Y/n eyes slowly open as he felt a presence hiding in the dark of the woods or more like in the top of the tree.
Y/n: "You're bad at hiding your presence, Ken. Did you got training while I'm gone?"
The person jump in front Y/n, causing the dust to covering it's figure. As the dust cleared, there was stood a young male wearing a green jacket and grey shirt. His brown hair was swept by the wind and both of his ears covered in red headphone.
Ken: "Heya, Boss!!! Long time no see!!!"
Y/n: "You haven't answered my question, but whatever"
Both of the giving a bestfriend handshake ever (inserted Kakyoin and Polnareff handshake) while laughing together like an madman.
???: "You need to be strict with him, My King. He always bring trouble when you're not around. *Sigh* You should scold him as hard as you can"
Y/n: "Oh!!! Ren... How are you?"
Said Y/n to his other bestfriend. He has dark-brown hair and wearing an silver plate mail. This person is Y/n's Knight, he is very strict to his subordinates especially to Ken.
Ren: "I'm fine, thanks but the one who need that questions is Ken!!! He's fooling around too much that caused me got headaches"
Ken: "Blabalabla... Shut up!!! Are you my mom!!???"
Y/n: "Hai~ If you don't stop there, I'll bring my other self to bitch slapping both of you"
Both of them shivered, hugging each other like a bestfriend as Y/n mention Sir. Hell name. The sight of Vietnam war will be in their brain if the Trainer from Hell arrived to their presence.
Y/n: "Where Nanako and Yagurou???"
Yagurou: "We are here, My lord"
Said the young Ninja as walking our from the tree shadow while the other one is walking beside him. Nanako grew tick mark as she still sleepy when Y/n call them.
Y/n: "The reason I called you here, because it's only our chances to help Kuroka and our Queen. We'll training the Gremory for upcoming Rating Game and got our rewards from her brother... I expected all of you to give it best as you can"
All: "Yes!!! My King!!!"
Y/n's peerage kneeling in front of th young King, causing him to smiles sweetly to his subordinates.
Small Timeskip
It's 5 in the morning and Y/n decided to wake up the Gremory as he entered their room one by one but grew a tick mark as all of them still sleeping in their persona bed. Y/n casted simple water magic, on their head and leaving the room.
Y/n: "WAKE UP!!! FUCKERS!!!"
The group yelled as cold water splashed in their face and they're rushing their feet find the way to first floor. Their face filled with anger but reverted normal as Sir. Hell was more pissed at them.
Y/n: "Time to training, fuckers! I'll give you ten minutes to wash that disgusting face of yours and meet me outside. if you're all late for even one seconds then.. PREPARE FOR PUNISHMENT, MAGGOTS!"
They rushed back to room, taking shower and then changed to workout clothes. They running back to outside, didn't want to anger Y/n.
As they're outside, waiting them is not only Sir. Hell anymore but there few peoples they didn't recognized.
Y/n: "Good! You're all on time. Oh, and they are friends of mine, they will help with your training"
The Astaroth's peerage stepped forward, revealing their serious face while facing the Gremory.
Y/n: "Nanako will train Koneko to improve her speed, Yagurou help Issei train 'How to be a good pawn', Ken will train Kiba, Ren help improve Seinna her sword art and martial art... Finally! Akeno, Rias and Asia will train under me!... Go! We don't have time to wasted!!!"
- With Nanako -
Both Nanako and Koneko in the deep of forest and preparing for training.
Nanako: "First, focus your strengths into feets and kick the ground as hard as you can"
Koneko nodded, focused her strength into her feets and kicked the ground with her all might. She widened her eyes as got in front of tree in the blink of eyes and crashing into woods.
Nanako: "Ouch, That's definitely hurt. Okay, let's control your strength first after that let's train on your reactions time and also reflexes..."
Koneko: "Ugh...Hai"
- With Yagurou -
Yagurou and Issei can be seen jogging together, improving Issei's stamina. Their destination is in the top of mountain and they'll back to the mansion as finish line.
Yagurou: "I see, you're Milord little brother. I've heard about you from him when we are on missions"
Issei: "Not by blood but he's already like my family... What is he talking about me?"
Yagurou: "That's you're a pervert and told me and he choose a wrong brother for him"
Issei: "*awkward laughs* That's like him. But, he really care about me even with my perverted behavior and I missed him after seven years we apart"
Yagurou: "I see... Oh! That's our destination"
As arrived in destination, Yagurou pointed Issei to take a rest for five minutes as give advices, how to be strong pawn.
Yagurou: "Issei, as pawn you needed to be a Juggernaut... I'll train your martial art as your main weapon choices, for your magic part, I'll let Milord trains you because he knows about that aspect more than me, also let's shape your body"
Issei: "Hai, Sensei!!!"
Yagurou chuckled, as heard that. When they are got enough rest, Yagurou and Issei decided to jogging back to the training camp.
- With Kenmaru -
Kenmaru mentioned Kiba to follow him, and guide him into the grass field not far from the mansion. Suddenly, stopped his movement, Kenmaru rush toward kiba and send kick toward the Knight. Kiba stepped backward, dodging it's attack.
Ken: "Let me tell you something, I'm bad with words and boss just told me to beat the shit out of you. So, come!!! I'll crush every swords you throw to me!!!"
Kiba summoned his Holy Eraser and Flame Delete at the same time as Ken only stood up and rising his hand, opened it's palm. Kiba vanished from Ken's sight, causing him to sighed heavily and inhale a huge amount of oxygen.
Ken: "Flow of Empty Sword - Iris"
Ken dash forward using his footwork, causing him to fluidly leaving afterimage. This caused Kiba to confused, even with his speed, Kiba having hard time to see Ken's movements. As Kiba feels Ken in front of him, he slashed both swords in a X arc, but it's only slased an afterimage.
Ken appears on Kiba side and sending a roundhouse kick toward Kiba's shoulder, an following up attack to Iris once the opponent strikes illusion. Kiba sent flying with much force from utilizing Ken's speed and movement, causing the Knight to falls concussion while crashing into woods.
Ken: "Too weak!!! Now! Let's do another round- Huh? Did you fall asleep?"
Kiba who's already fall concussion, caused Ken to scratching his head in annoyance.
Ken: "*Sigh* This going to be a heck of a long day"
- With Ren -
Ren facing against Sienna in sword style combats. Judging, the young prince need experience Ren keeping up with her only with frame of his strengths.
Ren: "You had good movement even with that big sword, but don't use any magic yet. Let's improve your arsenal skills first"
Sienna: "Hai!!!"
After ten minutes class of sword, Sienna grew tired as her hands trembling from holding the sword.
Ren: "Let's take a rest and continue our training. Next time.... I'll GET SERIOUS!!!"
Sienna widened her eyes, she thinks this boy was got serious when facing her, and yet he stated that he was playing the whole time.
Sienna: "Are you all kinds of Monsters?!!!"
Ren: "Why? Thank you... If you had energy to talks then let's train your martial art... COME!!!"
Sienna: "Hai!!!"
- With Y/n -
Y/n told Akeno and Rias to shot out their magic till they dropped to improve their magical reserves while for Asia, he was trying to improve her Twilight Healing.
Y/n: "SADISTIC QUEEN! PERIOD HEAD! I'LL IMPROVE YOUR CASTING TIME AND MAGIC RESERVES AS WELL THEN WE MOVE TO IMPROVE THE WAY YOU USED THAT MAGIC OF YOURS!"
Y/n: "Asia! For support I'll teach you support magics you'll need. First, let's improve that green light heal of yours and after that lets learn Bind Magic for you!
Y/n: "Did my guides is clear!!!???
All: "Sir! Yes, Sir!"
Y/n: "Good! Now, Go!"
Y/n and his peerage members give their best to train, teach and guide the Gremory to improvement in skill and ability they had. It's come joys for them to training the inexperienced devils, even when Y/n still had grudges against Rias. Without knowing, the Gremory team has chances to becomes strong peerage.
Time skip 3 Days
???: [Ahh! Finally I can talk...]
Issei: "The heck??!!!"
Issei surprised by the voice as Red Gauntlet deployed itself in Issei's arm.
???: [Why did you surprised? Oh, I'm the Welsh Dragon Ddraig, one of the two heavenly dragon]
Rias: "*Gaps* it's incredible!!! It's only 3 days, and Ddraig was able to speaking through the Boosted Gear. The training really pays off!"
Y/n: "You still have 15 days... don't get too excited... I'm planning to let Issei reach Balance Breaker..."
Said Y/n, causing the peerage widened their eyes, interested to Balance Breaker Issei will have, even the Welsh Dragon interested as well.
Ddraig: [Indeed, If my partner keep training at the same rate it's possible to reach that form in 15 days. You have my thanks, Young Devil]
Y/n: "You can say that after Issei able to master it"
Issei: "Balance Breaker???"
Y/n looked disbelief at Issei and looked toward the Rias who's averted her eyes, not dare meet Y/n's eyes. Y/n sighed heavily as know Rias didn't provide Issei or Asia about the Sacred Gear.
The days ended when Rias give Issei and Asia information about the Sacred Gear and the Balance Breaker while Y/n and his peerage training theirselves outside the mansion. An madman laughs can be heard in entire mansion causing Rias's team shivered in fears as back to their own rooms and falling sleep rather fast.