Third P.O.V
After many months of training with the four in the unknown dimension which the young male learn it was a projected version of the thrown of hero's of humanity past from stories of long ago.

At first it was very difficult for the young male to train with these people, the first among was the raven hair man named Kiritsugu emiya in life he was refer to as a simple mage killer for hire but after his death from the fourth grail war he passed away and was now a member of the assassin class. Y/n learn a great deal of time alteration spells that allow him to speed up or slow down time on a target in combat to use to as a advantage, once the training with him was done out of respect the young male crafted blade/guns for combat.

For the next part of training for the young male is was to learn elemental and weapon creation magic for the caster servant known as Skadi and a powerful hero/witch from another world named Nine of phantom. In the beginning from learning from both of them the young man worked hard to learn and study from them both personally was no small feat.

During this period he grew very close to them both and they the same to them, during a test to retrieve flowers the dragon form of Siegfried the dragon knight wasn't so simple but he was lucky enough to pull through and he gain instability/regenerative power aswell from the evil dragon blood but this change his hair and eye colour from (l/n) to red hair and (b/n) to yellow eyes. Once the trail was done he return with the flowers for both of them and with a wrapped arm in cloth, to which he was given a new outfit that looked like one from a different time with a red bandanna on his forehead.

The blonde hair male is the final teacher to the young Y/n, he is Gilgamesh king of hero's and during the training the young male use his new found magic to recreate all most every single weapon from the king noble phantasm the gates of Babylon. However he was not able to replicate two of his majesty most strongest weapons known as the chains of heaven gifted to the king from his only friend in life Enkidu and the other a powerful sword known as EA, a blade that can't be stopped from destroying whatever be in its way.

"Well done mongrel upon when you first arrived here you couldn't survive all of our full power assaults on you but you began to adapts to all of our styles of magic and combat. I can't see a better modern version of myself in human form now rise for you have a fallen dog to destroy, then you kill that red lizard host" Gilgamesh tells Y/n who rises from kneeling to his former teachers with a calm and cold face with a battle ready posture.

"This will be farewell for now but I couldn't have chosen someone better to train by my magic skills and here this is for you, it's a location to a old but still usable safe house" The mage killer gives a letter and green crystal key to his young apprentice who takes it and bows to his former teacher before standing up right again.

"I will admit this much I didn't see you survive past your first month of training here but you surprised me so take this as a reward from me and once you have place to yourself I might just stop by to see you~" Nine tells Y/n with a flirty smile before grabbing his top part of his outfit pulling him towards her and she shove her tongue into his mouth to give a passionate/forceful quick make out.

"Nine we agree with both could have a turn with him" Skadi pulls the hero/witch off her former student before putting her lips on Y/n to give him a kind and pleasant kiss, she then put something into a pocket of him before she pulls away and puts her hand on his cheek while giving him a kind smile.

"Now go and show the factions the true power of humanity" A purple portal opened up behind the Y/n to which he was push into that shut behind and on the other side it reopen in kouh close to the school to which Y/n turn towards before he use magic to increase his speed to get there.

Kouh academy the battle of Rias peerage vs kokabiel this is brought to you by

The battle for kouh wasn't going well despite Rias and her peerage best effort against the fallen angel general Kokabiel, every attack they would throw at him would do nothing and they were running on low magic power and to rub salt into the wounds the general told that the Christian god is dead and has been for since the Great War.

"As much fun as this has been princess of annihilation I say it's time to end this here and now, I grow bored of dealing with children- AGh!" Kokabiel is interrupted from his taking by taking arrows in his back and they clipped most of the left side of his wings making him lose balance and land on the ground.

What the? Who did that?" Issei questions as the fallen general rises to his feet only to be shot in the knee caps from bullets from a mysterious person but the red dragon emperor felt like he knows this person.

"Kokabiel prepare to die" a voice spoke out loud in a cold and deadly tone, Kiba and Zenovia turn there heads to the school to see Y/n standing there making a bow and sword appear in his hands.

'What's the? It's like my sword birth but by his power it's completely different level' Kiba thinks to himself before he and Xenovia get back into battle with freed. Y/n sword  or it's accurate name as Caladbolg then turns into a more compact form of a arrow and loading it into his bow firing it with magic to strength the shot.

"Face the judgement of humanity" Y/n release blade into the air brim his bow and it shot at intense speed towards the fallen right into his head, but the magic infuse with the attack also cause the body to employed only leaving black feathers remaining.

"No way how can one person do that?" Rias questionas she turn to notice that Y/n is now gone as fast as he came from the battle, but Issei then felt a cold chill run down his back and he heard his brother voice speak within his mind.

"Pervert red dragon emperor know that I will be the one that takes your miserable life very soon" The magic barrier then shattered to reveal the arrival of the white dragon emperor but Kiba and Xenovia have one question on there minds.

'Who was that person that killed Kokabiel and what he intend to do next?'

At a disclose location brought to you by

Y/n now reappears in the location given to him by Kiritsugu to show a cabin the woods and a small one at that, y/n looked at from the outside before he began to walk up to it.

Y/n then inserted the green key into the lock and turn it to walk into the place that even though has not been use in a long time is still clean and up to living standards.

'I'm exhausted, I'm just going to find the master bedroom and just sleep, I will deal with the devils tomorrow' the young male shuts the door behind him and locks it before heading further into the cabin till he found the master bedroom to which he use his magic to bring him his old clothes from before his training and he use his magic to make his combat attire disappear, he then climb into bed and fell to sleep.

The next day at kouh academy

"All right students we got a new or should I say old student coming back from a long trip of learning so he got bump up to second year aswell" the teacher spoke in Kiba class to which everyone in the room settle down and the door open to show Y/n in his new appearance enter the room and then stand infront of the chalk board with a smile on his face before he spoke.

"Hello Y/n here" Every student in the classroom was surprised to see him back after what felt like a long time for them but to Y/n it felt more like eternity since he was at the throne of hero's.

"Y/n you sit next to Kiba, Yuto please stand up" the teacher told the blonde devil who rose up from his seat to with the other male walk to the Vacant seat and Kiba sat back down in his own while the teacher began to lesson.

'Something is different about him, maybe I should tell Rias or just talk with him by myself?' Kiba then focus on the lesson while Y/n keeps a calm look upon his face but in his mind he was thinking of when he want to end issei and in what matter.

(Hello my readers I hoped you enjoyed this second chapter after so long, what did you enjoy the most about it and let me know in the comment section. Also what do you all think Kiba should do about you the reader?
Should he:

A) tell Rias about your return and change

Or

B) Confront you about your disappearance from months prior

(Any way I will catch you all in the next chapter and stay healthy along with those you care about)