The Last Sharingan Holder (Male Reader x Highschool dxd) (Fixed)

Power-Up

POV (Y/N)
"Hey girls, I need to tell you something" I say after my spare with sensei
"Yes love?" They ask in unison, I chuckle and they giggle
"I'm going out for a bit, so if you need me tare this*hands them a paper with a emergency notification seal* once torn I'll be alerted and come running" I say and Akeno asks
"If you don't mind my asking, where are you going on such short notice?"
"Not at all, and I'm heading home, I heard from a contact that they found a hidden lab and I want to see if there's anything useful" I say as I change into my ANBU outfit
"Ok, just please be safe" Kuroka says with a worried look, I smile and kiss them both
"And do something to never see you two again, wouldn't dream of it" I say, they blush and smile then kiss me again before I Kamui home
Time skip outskirts of the Leaf Village, or what's left
"Damn, place seems worse and worse every time I come here" I say as I see the ruble that was once the great leaf
"You come here often?" Sensei asks
"I make it a point to come here every so often, like on mother's and Father's Day, or on one of my family's birthdays" I answer him as I walk to a certain ruble pile with two mounds of dirt and planks at the far side of them
"Hey mom, dad sorry I haven't been here in a few months. Training and hunting take a lot of time, I got you guys something" I say on the verge of tears, I keel and place two bouquets of flowers on the graves after that I can't hold my tears anymore and cry. After a second I'm pulled into a hug from non other then Asura-sensei, I'm surprised at first but quickly melt into it and cry on his shoulder he says nothing as he rubs my back in a comforting manner. This continues for a few minutes till I recompose myself
"Thank you sensei, I needed that" I say as we stand
"I'll always be here if you need a shoulder, as weird as it is, and despite the short time, I see you as my family so I'll always be in your corner" he says in a fatherly tone and I hug him again and he returns it, we separate and I clean myself up and say
"Right, let's get to that lab" he nods and I lead the way
POV Asura
"You have my word, I'll keep him safe no matter what" I think as I look at the graves of his parents I start to fallow him
"Thank you" a pair of voices call out, I swivel my head back and see no one but I have a guess as to who that was. I smile and nod before catching up to my student/ son figure
POV (Y/N)
"This must be it" I say looking down at a heavily armored hatch, after walking for a bit we found it under the ruble that was the Hokage tower and thanks to sensei it was easy to uncover, I make a clone to open it in case it's boobytrapped, sensei and I back up and he opens it nothing happens immediately but we still proceed with caution as it may still be trapped further down. However after a few minutes of walking we enter a stereotypical lab beakers and test tubes decorate the tables, a occasional microscope here and there but one of the cabinets is full of scrolls from jutsu, summoning contracts, and research notes. But one big one beside it catches my eye and upon further investigation it's the scroll of forbidden jutsu( the one Naruto steals)
"Jackpot" I say
"What's that?" Sensei asks
"This is the scroll of forbidden jutsu, only the Hokage can see it, unless your my grandfather and steal it then read it" I say and he sweat drops
"How did he become a leader acting like that?" he asks rhetorically
"Simple, he never stopped moving forward never stopping no matter the obstacle he found a way to persevere" I answer and reminisce about my time with him, after my trip down memory lane I put all the scrolls into a seal I have tattooed on my left wrist and keep looking
"Oh, what have we here?" I ask as I find a sealed preservation chamber, after a moment I find a button and press it, opening it, and inside is a vile of a white substance. Upon further investigation I find a label on the side and when I read it I nearly have a heart attack
"Holy shit" I say gaining sensei's attention
"What you got there?" He asks walking over to me
"These are Hashirama cells, copies of the first Hokage, the God of shinobi. Injecting them into you gives you some of the properties of his family, the Senju, but I'm a distance relative of them but I can still use this to up my chances of unlocking the Rinnegan" I answer quickly in excitement
"Not sure what you said, but I'm glade your happy" he says, I nod and find a needle to use after I find one, and sterilize it, I inject some into my arm, I left enough to make more, after I make sure nothing is wrong I clean up and store the cells in a freezing seal so they don't die. As we're about to leave I check the bookshelf for anything important only to accidentally open a door
"Cliché" I say and walk down the spiral stairs, this reminds me of how I met Kuroka and Koneko
Flashback still you POV
"This is just sick" I say as I look out at the sea of cages with corpses in various stages of decomposition, I was tasked with investigating a noble that has been acting weird, but to think his doing illegal research for the old devil faction. As I'm about to leave I hear shuffling from one of the cages and go to investigate upon doing so I find a girl close to my age with black hair and golden eyes, and a younger one with white hair and the same eyes both have cat ears and a tail the same color as their hair. They both seem malnourished and scared, so I gently ask
"Are you ok?" I startle them and the younger one hides behind the older one
"You won't touch her, just experimenting on me!" The black haired one yells and my suspicious are confirmed as to why they are here. I shake my head and cut down the bars with my katana then sheath it, and turn to the girls still scared
"No need to worry I won't hurt you, I'm (Y/N) who are you?" I ask gently, but inside I'm burning with rage, this bastard better hope he's arrested before I get a hold of him.
"Why should we trust you, you'll just hurt us too" the black haired girl says and I removed my mask and see her blush
"Because why would someone your age be here, and not in a cage, other then to help?" I question and see her considering it but the door to the lab opens and I see them flinch I turn and put my mask back on before drawing my sword. A older, bald man walks to the cage flipping through a file before dropping it at the sight of me and the destroyed cage
"Who the Hell are you!?!" He shouts and I tighten my grip on my sword and say
"Who I am doesn't matter, Nathen Rothelo for the crime of treason, illegal experimentation, and others you are sentenced to death" I say and look at the girls
"You might want to look away and cover you ears" I say and they do, I look back at the man and rush him too fast for him to register and decapitate him. I clean my sword of his blood before putting it away and returning to the girls to comfort them, eventually they are taken in by the Gremorys like I was and grow up along side us like a normal family. Kuroka eventually confessed her feelings to me after discussing it with Akeno and I returned her feelings and we've been together ever since.
Flashback over still your POV
By the time my second trip was over we reach the bottom of the stairs and down a long hallway to a massive metal door with writing on it I recognize it as what's like in the Uchiha compound, so activating my EMS (Eternal Mangekyo Sharingan) I read the door aloud
"If you are reading this then the village has been destroyed or is in threat of, behind this door lies the power to save it or doom it. Pass the trial and that decision is up to you, but be warned for this challenge will kill you if not passed" after I'm done I deactivate my eyes and look at sensei
"Don't know why your looking at me, I go where you go" he says, I smile and nod then approach the door ready to face the challenge head on
Time skip
POV Akeno
"So he's here?" I ask Sona as I look at the barrier around the school, she nods and I go to rip the seal (Y/N) gave me but I'm stopped by Rias
"Let's handle this without him" she says and we all look at her like she's grown a second head
"Think about it, he's handled every big fight for us, and strong he may be, he's still human and won't be around forever like we will. So let show him we will be ok without him holding our hand, because if not now then when?" She defends her statement, and she has a point he's dealt with most of the fights for us, and to grow we must learn to fight for ourselves
"Let's do it" Sona says
"I'm on board" Kuroka says
"Let's do him proud" the rest of the peerages say
"Oh what the Hell, let's do it" I say and put the paper away
"Are you sure?" Sirzechs asks and we nod, he does the same and heads into position with the other leaders, while we enter the dome.
(This happens the same as the anime, but Kuroka and Gasper are there, and Irana is knocked out by a Cerberus, with the leaders and a strike force of the three factions watching and waiting)
POV Rias
"Damn, so close all we needed to do was beat Kokabiel and we would have won!" I mentality yell
"Congratulations, Rias Gremory you and your peerage did a fine job at distracting me. However you just fall short of the finish line" he says
"Honest praise, we'll generously take it" I say at least we know our limits and can improve, if we survive tonight, he then raises his arm and forms a massive light spear to end us, and because of our exhaustion we can't move
"If only you had brought back up, then you may have won" he says and I see the leaders about to interfere, but before that can a new voice rings out
"Oh but they did" it says and something slams into Kokabiel and stops him from throwing the spear
"I'm pretty sure I told you to call me if he showed up" the voice says in a scolding tone and I now see the source it's (Y/N)...flying!?!?
"How can you fly, your human!?" I shout and chuckles before saying
"I had a bit of a power up, but that's not the point. I'll deal with crow face then you can explain to me why my existence was forgotten"
Kokabiel flys to the same level as (Y/N) and says
"This is the fabled "False Gremory" I have to say your strong, perhaps you can give me a proper fight" he then forms a sword of light and (Y/N) draws his sword and activates his Sharingan, after a short stare off they rush each other and clash swords creating sparks they then disappear in a blur and all I see is a firework show, sparks left and right, thunderous booms fill the sky after a few minutes of this they suddenly appear about twenty-five feet from each other, both having smiles from ear-to-ear, Kokabiel chuckles and says
"I must say your quite strong, I haven't had this much fun in a fight in ages" (Y/N) chuckles
"I'm in the same boat as you, it's good to not hold back as much" he says and shocks me and the others
"Your holding back?" Kokabiel questions with a curious look
"Not so much holding back, as can't control my full power" he says sheepishly rubbing the back of his head
"Anyway, I'm afraid you can't win you are a simple human, and I am a Fallen Angel the strongest of the three factions. No of all the supernatural world!" Kokabiel declares and (Y/N) just sighs
"Seriously you too?" He says in a defeated tone
"What do you mean by that?" Kokabiel asks in a annoyed tone
"It's just all the factions, not just Christian, have this sense of supremacy blinding them from working together to benefit all, but instead they tear each other down" he says
"You have to admit if we put aside our differences and worked together then this world would be so much more advanced" he continues
"You have a point, together they can do a lot" Kokabiel says in a honest tone shocking us
"But unfortunately, Heaven and Hell have lost their leaders" he continues confusing us
"What do you mean Heaven lost its leader?" Rias questions and I go wide eye at what he's saying
"Oops that just slipped out, oh well I might as well tell you I am trying to start a war after all" he says and I send a fire ball at him at the same time as a ball of destruction, light spear, and a halo. All of which he avoids and continues speaking
"You see during the last great war God and the old devil leaders died" he reveals
"Also when did you three get here?" He questions the leaders
"We used your little attack to prove that we can work together, in hopes it would sway the nonbelievers. Didn't expect you to reveal that big secret though" Azazel says
"It's not true is it?" Asia asks desperately
"I'm afraid so child, I have be running things in Heaven since after the war" Michael says with a sad tone. She can't handle this and faints, I on the other hand grow angry at not stopping him in time
"Ko-ka-biel" I say and decide now is as good as time as any to test what I got from the lab. I sheath my blade, close my eyes and focus, focus on the energy flowing through me I let it build in my stomach and all at once let it explode outward, unintentionally, sending everyone flying and destroy the barrier once the dust is gone I reveal my new form to world
POV Kokabiel
"The Hell is with this brats power?!?!" I panic in my head but on the outside I seem angry, but I'm really scared.
"There's no point in hiding it Kokabiel, I can see your heart pounding from here" he says and I get close look at his new form, his skin is completely white apart from six black symbols across his chests, his hair has become snow white as well and his left eye has become purple with black rings bearing the same symbols on the rings as his chest. His right eye has the same patter as the start of the fight but the red is now white and he has veins bulging around his eye. In addition he has eight black spheres floating behind him in a circle, his power is also off the charts, I may have made a mistake.
POV (Y/N)
"Damn, this is straining" I think
"At your level you can only hold this for fifteen seconds without risk of death" Sensei warns
"That's all I need" I reply and charge him, but to the others it probably looks like I teleported in front of him, I slam my fist down on his chest and he rockets down. But before he can touch the ground I move and kick in back up, five seconds left need to end this, I quickly form hand signs and take a deep breath and use a Jutsu of my own making
"Fire style: Hunt of the Fire Dragon Nova"
I call out in my head before exhaling and massive plum of fire that forms into a eastern style dragon and flys towards him with waiting jaws, once it catches him in them he screams out in pain but it's not over yet the dragon coils around him, like a snake does it's prey, before compressing into a sphere of fire then all at once explodes sending me, now back to normal, plummeting to the ground and into unconsciousness
POV Sirzechs
"What the Hell was that?" I ask to no one in particular
"I have no idea" Azazel answers
"I'm just glad we weren't it's target" Michael speaks all our minds, this is proven by everyone nodding, after I'm done staring in awe I go to check on him only to find his head in Akeno's lap with her stroking his hair
"It seems he tired himself out, can't remember the last time I saw that" I say and smile as he's getting closer to his goal I then send Rias and her peerage home so I can repair the school but Sona stops me and says it's her job as school president to do it so I let her and return home to brief the other kings on today's events and silently thank (Y/N) for all he's done.

Boom longest chapter yet, hope you enjoyed.
Also it may seem like I'm giving the MC a lot of power for no reason but I will reveal how he got it in the next chapter, this one is long enough so please be patient.