Rias and the gang stood in front of Kouh academy as the student council held up a barrier the gang was about to face off against a leader-class fallen angel and were unsure if they wanted to contact Sir Zechs about the situation

"Rias, I understand that you don't want to be a bother to your big brother. But the enemy is a leader class fallen angel. We're gonna need all the help we can get." Akeno informed before looking at Issie with a determined look. "I had also called Y/n and his peerage as well. Let's have the devil king and Ra's champion to back us up." this caused Rias to give out a sigh of defeat. " Thanks for your understanding, Preisdent." She smiled at Rias. "Sir Zechs' forces should arrive in the hour. Y/n told me he would be here in ten minutes. Something about being stuck in a match."

"Senpai is playing a video game while this is happening?" Issie asked thinking of what kind of game it was.

"He didn't know until this moment." Akeno smiled.

"my, I can't win against you can I?" Rias joked before turning back to the barrier. "One hour huh?"  

Walking into the schools front door Rias laid out her plan. "Issie, I'll have you on as support." 

"Support?" This questioned the pawn as he looked at her wondering if him just being in the fight would help more.

"I want you to use your ability to transfer your power to the others to raise their power."

"I see.Roger!" 

"We need to stall until Issie can transfer his power to all of us." Rias smiled looking back at the rest of her team minus Kiba.

"I understand." Akeno smiled as Koeneko replied with a "Yes, President."

"Issie." 

"Yes?'" He asked Rias as she smiled at him.

"We're counting on you. Show your sensei how strong you are." She smiled referring to Y/n in that last sentence. " We need to be on the offensive during this match. We can't let Kokobiel use his full power here. Unlike our fight with Riser, Our lives are on the line. But I won't allow us to die. My dear servants, survive so we can go to school together again!" She motivated as they all agreed with her.

Outside in the courtyard everyone noticed the holy swords of Excalibur being fused into one with a strange amount of magic being poured into it. "So is Sir Zechs coming or maybe Serafall?" Kokobiel smirked.

"We're here in his place." Rias informed the fallen angel.

Snapping his fingers he summoned a massive light lance before tossing it at the gym causing it to explode sending Issie back on to his butt. 

"The gym.." He said in shock at the destruction.

"This is boring. Ah well, a little diversion can't hurt." Kokobiel smirked looking down at the group.

"You're kidding?" Issie asked clearly shaken up by his power.

"are you scared, Partner?" Ddraig questioned as Issies left hand.

"I've never seen such a big lance made of light. It's like it's from a different dimension."

"Of course it's from a different dimension. We're talking about a man who survived against God and the Devil King."Ddraig said a bit amused by his host.

"can we really beat that guy? Can senpai beat him?" 

"When it comes down to it, I'll beat him even if I have to turn most of your body into a dragon."Ddraig told him.

"Most of my body huh, So that's the level he's at?"Issie smirked trying to get rid of his nerves.

"Since you came all this way, I suppose I'll have you play with my pet." The fallen angel smirked before his throne shot a pillar of light from under it as it collided with the ground. 

A massive magic circle appeared as the ground opened up showing hell. A massive pillar of fire appeared as a figure of a massive three headed dog rose and climb out crushing the ground underneath it. 

"Cerberus?" Akeno called out as the dog looked towards them with flames spilling from it's mouths. 

"Living at the gates of the underworld, It's the watchdog of Hades." Rias told her pawn and bishop as Asia looked up with slight fear.

"The watchdog..... of Hades...?" she said with fear in her voice.

"To bring that to the human world.... Let's go, Akeno. Koneko!" Rias ordered as the three of them rushed in."Issie, use the sacred gear to enhance our power!" 

"Yes, President. Boosted gear!" He called out as his red gauntlet appeared on his left hand as Ddraig yelled out "Boost!" "Asia, Get back." He said pushing her behind him as a second Cerberus appeared attacking the girls. "Don't worry they'll handle those puppies like nothing." He reassured Asia to keep her calm during this attack. "Damn it, if only i was stronger I could transfer my power to them in an instant." he thought to himself before hearing Asias scream.

"Boost!" 

Turning around he grabbed Asia and moved the both of them away seeing a third Cerberus. Moving back a bit Issie looked in annoyance. He knows if he attacks or is attacked He'll lose his counters and will have to start all over again. 

"Asia stay back I'll lure it away from here." he said moving away from her with the giant dog running after him. Dodging an attack from the massive dog he flipped in mid air but one of the three heads went to chomp down on the red dragon emperor until a female fist punched it in the eye making the dog stagger. Landing on the ground in front of Issie he looked up seeing the help he got.

"You're." 

Standing in front of him in a boxing stance was the rook of Y/n as she rushed at the dog. "Leave it to me." Isabella yelled as Koneko kicked the dog in the chin making it roar in pain. Just then one of the heads of the Cerberus that was fighting Akeno and Rias was cut off as Carlamain landed on the floor with her sword drawn. 

"I really needed to work on my sword work." She said glaring at the beast before a massive explosion went off underneath the same dog as Yubelluna flew in between Rias and Akeno.

"Sorry it took us a while." she apologized making the girls smile.

"Don't worry about it. We're just glad you're here." Rias reassured as they flew in the air.

"Oh? The Rook, Knight and Queen of Riser?" Kokobiel smirked at this interaction "Tell me where is that chicken?" He asked making Yubelluna look at him with a smirk. 

"Why would I know? I'm not his queen anymore." This statement raised an eye brow from the Fallen angel.

"Then you're strays? Fine with me I'll put you down as well." He smirked before summoning another massive lance but it fizzled away making him look in intrigue. 

"Yeah that's not gonna happen." A calm and collected voice called out making Kokobiel look to the side as Y/n appeared with his arms crossed as he was equipped in his armor. 

"Oh and who are you?" He asked before Y/n chuckled.

"Makes sense a freak like you wouldn't know who I was." He said before giving Kokobiel a powerful right hook sending him into the ground. "Oh come on Kokobiel that was just a love tap." He smirked before landing on the ground.

"Boost!" 

"Issie go transfer your power to your president and vice president." Y/n said before walking towards Kokobiel as he was getting up.

"Right!" He replied before running towards Rias and Akeno but one of the Cerberus dogs was about to chomp down onto him if it  wasn't for Xenovia as she cut through it with Excaliber destruction. "Xenovia?!" 

"Looks like I made it just in time." She smiled before running and cutting the second one with the help of Carlamain. 

"You're late." She told the Excalibur user. 

Kokobiel stood up slowly as Y/n stood in front of him. The fallen angel smirked a sense of nostalgia hitting him like a wave. Quickly the Angel began to laugh. His laughing confused the Sun Dragon Emperor.

"What are you laughing about?" He questioned making the Fallen Angel look at him with a smirk.

"I know your voice. A hint of nostalgia to be honest. Cadet L/n. " He smirked making Y/n raise an eyebrow. "Tell me. How was your time in that war with Vietnam? A boy as old as you must've travelled a lot right? Surely you didn't forget about that friend of yours. What was his name?"

"Shut up." Y/n threatened making the Fallen angel smirk. 

"Y/n calm down the Sacred Beast are trying to break through!"

"Ah, I remember now. It was (B/F/N) wasn't it?" He smirked looking at the boy. "How did he die again?"

"Shut up." Y/n glared as his armor began to shift and change. "If you know what's good for you." He threatened as the Fallen Angel just laughed with the sky blackening and lighting forcing through the dome as the student council tried to hold it up.

"What's going on in there?" Sona asked herself as the bolts kept raining down.

Everyone looked at Y/n after killing the final Cerberus as Yubelluna flew to Y/n's side seeing his anger rise. Y/ns body began to twitch as he started getting his memories flooded with his friend.

----"Hey Y/n why don't we get some milkshakes at the local diner?" a memory played.---

 "Y/n calm down. Don't let them control you." She soothed as Kokobiel smirked before yelling at the boy.

----"Heh you're my best buddy Y/n. of course I want you at my wedding." he smiled.---

"That's right! protecting you from a hand grenade. His entire back was destroyed and you wanted to save him but couldn't. All because you were surrounded by so many people and you didn't want to blow your cover!" 

---Y/n began to remember his friend in his arms with blood leaking onto his uniform as he friend smiled weakly at him. "Protect...my family for me.....okay?" Y/n's eyes widen as his breathing stopped. ----

Y/n's energy began to skyrocket but it vanished as he started to remember the good times. Before it was replaced by a pained look.

"Kill him!" The three Sacred beasts yelled as he grabbed his protected head. Collapsing onto his knees Y/ns head felt as if someone was scratching at his brain with a metal brush. "Kill the angel Y/n. Do it, put him in his place."  The three voices echoed as the boy started to stab his stomach with his claws trying to make an even worst pain than this headache.

Yubelluna tried to talk to him. Trying to have him not lose himself. But her words fell on deaf ears.

"I-I refuse." He said making the three beast growl at him

"Kill the angel. Don't let him talk bad about your friend." They spoke but Y/n rose to his feet as his head was pounding harder and harder.

"I already told you no. You don't control me." He said as his body began to glow gold making him shine bright. "It'll take more than head games to stop me." He glared at himself. "You may have invaded my mind and my body. But you're forgetting who I am." He glared making his power rise. "I'm RA's CHAMPION!" He exclaimed as his energy erupted.

"SUN DRAGON BALANCE BREAKER!" Ra yelled out showing the monsters that they weren't in control.

Everyone looked at Y/n as his body shined bright before he took off at Kokobiel. 

"Divine!"

Throwing a punch Y/n collided with Kokabiel's new trick. A sword made of light. Y/n glared at Kokabiel as he smiled as if he was having the time of his life. Just then Carlamian appeared before slashing at him with her sword. But it was stopped by his second sword of light. 

"Yubelluna!" The sun dragon emperor yelled as she smirked before summoning a purple devil crest underneath him as Y/n and Carlamian jumped back seconds before the attack went off. Kokabiel growled in the plume of smoke before summoning multiple light spears. Throwing them with a wave of his hand the attack cleared the smoke before everyone tried to move out of the way with Issei protecting Asia. But this ended up making him lose his counters. Y/n had to lean back narrowly dodging an spear to the head as it went off and blew a massive hole into the school basically rendering it as rubble. 

Y/n stood next to Isabella as she was shocked by his power. But placing a hand on his rooks shoulder she snapped out of it before getting a nod from Y/n. If she wanted to sit this out he was gonna let her. Moving towards Kokabiel he cracked his neck and knuckles as Kokabiel smirked. The two moved closer to each other before their energies matched in terms of strength. 

"I haven't had this much fun in ages. Perhaps you are what I need for my newest war to start." He laughed making the emperor glare. 

"You're doing all this because you're bored? You're insane." Y/n let out before chuckling. "You won't get away with this with us around." He smirked with the angel doing the same.

"You are the same as me boy. You're bored with low level angels and devils. You need a proper opponent. Now let's make this fight the whole reason for my war!" His laugh echoed as Y/n went to throw the first punch to their brawl.