The Outcast

What if?: 'the awakening'

Explanation: 'Izuku was controlled by Shigaraki from the nanites that was injected into his body...shocking him whenever he got out of hand...since then he has no control over his actions...his identity hasn't been revealed and both red and green vials are injected at once into his system...causing him to go into psychosis and ended up becoming  mindless for the time being.
Of course the event that followed after was his order to kill eri during the raid...but avast in the last minute it was no use as Eri managed to escape on time...everything else remains the same until the assault on Tartarus...where AFO gave Shigaraki his quirk and blah blah blah you get the point...this is the final battle...Instead of the black vial...Izuku awakens his original quirk
side note: 'this was one of the plans i had for the outcast...izukus identity being discovered at Tartarus...but i know it would seem like a long time...but this was what i had in mind'

Izumi: "SHIGARAKI!!" 
Shigaraki: "hmm...and here i thought you would finally stop...it is too late...i have finally gotten the power i need...to end this order once and for all..." 
Izumi: "you think we're going to let you out of this...your wrong..we will prosper...and we WILL DEFEAT YOU!!" besides her are the rest of her friends and then...the big four...yes that's what they call themselves...
Shigaraki: "hehehehehe...you really think that you low leveled losers are enough?...no...it's not going to stop...not if i say so" but he then looked in a different direction...as the others look at the bogeyman there grunting and growling...but in his mind...his hatred...has returned...from seeing Izumi...
Izuku: "gnh gah...Izumi" growling out her name as he slowly walks towards her 
Shigaraki: "hey no...Don't waste your time on them!" irritated...like an owner upset with their dog 
Izuku: "Izumi!" as they see his hands have black veins on them...slowly walking towards them...
Izumi: "what the?" noticing how he's acting much more animalistic
Katsumi: "the fuck?" 
Bakugo: "grr...no...this loser is mine" as he rushes him
Katsumi: "FUCK WAIT!!" 
Bakugo: "HAAH!!" letting out a concentrated blast on him as the smoke clears 
Izuku: "IZUMI!!" seeing it did nothing on him
Izumi: "shit!...Listen here you freak some may call me that but You know where my brother is!" Nejire steps up towards them fearless despite the nightmare walking towards them 
Nejire: "where is IZUKU!!?!" once she said that...he 
Mirio: "where's are friend?!" 
Yuyu: "You give him back...YOU GIVE HIM BACK!!" Tamaki also nodding as he has his mantis shrimp arm ready 
Shigaraki: "tsk hahahahaha...it seems i don't have to wait long for the fun since my pet over here has other plans for you...ATTACK!!" pressing the button seeing him get shocked...but...it had no effect on him 
Shigaraki: "what?" stunned by this 
Dabi: "oh no" seeing this now
Bakugo: "FUCK THIS SIS!!" 
Katsumi: "RIGHT!!" now yelling out 
Bakugo and Katsumi now charge up their attack 
Izumi: "NO WAIT!!" too late...as the two released their ultimate attack on him point blank...smoke and dust enveloped the area...and right there in front of them 
Izumi: "*cough cough* is everyone alright?" looking at the others...seeing their expressions...filled with shock...disbelief 
Izumi: "wha...what are you looking a-" but she too sees it now...right in front of them...the bogeymans real identity...his outfit burned away..leaving only the combat pants...
Nejire: "Izuku" muttering his name out...crying...as they see the nightmare of Japan...was him....all along...their lost...friend 
Yuyu: "what the fuck" 
Tamaki: "no" 
Mirio: "Izuku...w..." as Izumi was speechless as well..knowing everything this monster did to her and everyone she knows...it was her own flesh and blood
Izuku looking down...motionless there was blood coming out of his nose...he then starts growling again....his eyes became bloodshot until
Izuku: "RRAAAAAHUAAAH!!!" as his pained roar echoed in the building, feeling the temperature increasing...forcing the heroes to fall back...as the screams of their lost friend and mentor...is in a state of rage...so much that he doesn't care who he hurts...then his body starts to glow a fierce green...chains sprouting from his body and melt again...as the white frost now started to build up...cold storm was then used...but the effect of it was dulled badly that they could stand in it...the building starts to shake and even molten rock starts falling from the ceiling...Continuing his screams...Izuku was seen being shocked 
Shigaraki: "STOP.IT!!..Izuku I told you to listen!...Your going to destroy the fucking building...ENOUGH IZUKU...I SAID ENOUGH!!!" continuing to shock him as Izuku continued to scream...but...as he was being shocked...something dreadful happens 
Izuku: "MUAHAHAhahaha...HUHAHAHAHA!" laughing as the electricity was traveling all over his body...thermite...chains...frost growing all over him as he continues to laugh shocking everyone most are in fear...Nejire felt hopeless seeing what they've done to him...how much they have tortured him...forcing him to become this...thing Izumi and the world had created...seeing the floor melting around him it started to bubble and his body begins to smoke...for what seem like an eternity....they all see his quirks stop working simultaneously...frost and burn marks are all over the room...bloody tears coming down his face, dripping off him...Izuku looks up shaking as he grunts in pain....before
Izuku: "RAAAAAAAAAHH!!!" hearing his voice cracking from his throat literally tearing...his eyes glowed brighter along with his mouth...then...they see the skin around his mouth starting to rip open along side his eyes seeing blood pour out of the tears as his eyes roll back...before...he exploded in a huge blast similar to a geyser made of fire...knocking everyone back...his screams echoing in the facility...Shigaraki could only stare at him in fear...in what he had provoked and created...as soon as the heat subsides to where its bearable to look...they now hear growling as they see the blue flames die down...in front of them...was Izukus transformed body...scaly...from the jaw all the way down to his foot...emerald scales...claws around his hands and feet...his chest glowed a bright blue where his heart is...he had a 'tail' made of flames and chains...as his eyes also had the same color and his thermite was now blue...seeing it flow right off him or burn off into the air...roaring like an animal ...Dabis breathing started to quiver...seeing his form...collapsed to his knees...filled with nothing but fear....Izuku stops growling...before he starts grinning...Euphoric with the power that has unleashed in him 
Dabi: "it's the one...true dragon" remembering tales his deadbeat father used to tell him...about How Firedrakes quirk seems to evolve throughout his bloodline...starting off as a simple fire quirk...letting out small balls of fire from their fingers...but as time went on...it began to grow in power...to letting their hands light on fire...to having tough scales on their arms...to his quirk...and now...now his son...is the perfect one...the perfect quirk
Izuku: "You Izumi..I choose you to be first of my victims!" his voice was rough, gritty, and raspy...pointing at her...as he snickers...
Shoto: "oh no you don't!" as Izumi and her friends snap out of it
Izuku now roars out at them...picking up his hammer he charges at them...breaking the concrete beneath him from the force of the flames...
Izumi: "MOVE!!" using her quirk to get them out of the way 
Izuku: "RRAAAH!!" as his chains gather around his chest...a ball of blue flames build up in his chest...to then be fired out...destroying the ground beneath him...Shigaraki stands back up
Dabi: "The beast has been set free"
Shigaraki: "How interesting!" seeing the others now taking this chance to flee the area...Dabi and Ochako stayed behind 
Dabi: "..." 
Ochako: "They're in trouble!...we have to help!" trying to help him up but
Dabi: "It's...it's no use..." 
Ochako: "huh?" 
Dabi: "he'll kill us....h...he'll kill all of us"  
Izuku: "hehehehehahahaha hahahaha!" lighting himself on fire he charges right into Shoka who defended herself with a wall of ice...but it explodes from the impact knocking her back 
Ochako: "what do you mean?" 
Dabi: "I...I've heard stories from...from my father but...I never thought it was true" clenching his fist from this 
Flashback 
Endeavor: "he is the true dragon of Japan...nothing will stop him should it be awakened...but.." 
Touya: "what are you saying" 
Endeavor: "he is the true villain in the making...A killing machine...with all of that power it will corrupt his very being" 
Touya: "You don't know what your saying...he could grow up to be a great hero! greater than all of us" 
Endeavor: "I know exactly what i'm saying... it's exactly what i'm worried about...in hopes of breaking his spirit..I'm sure your little brother and his plan will break him...to ensure he won't be a threat" 
Flashback ends 
Izuku: "RAAAH!!!" seeing the building started to collapse...the front part of tartarus blows up as Izuku now flies out of it using his extra limbs to propel himself out...he creates a large ball of flames and he throws it towards the city and he makes another towards the area the people are supposed to evacuate...hearing screams and shouts in the distance 
Izuku: "ah hahahahahaha" hearing the rest of the heroes coming up behind him 
Izuku: "If you wish not to fight i understand...But i will destroy this society no matter what!"  
Izumi: "No you won't!" now charging up One for all to see the green electricity dance off her
Izuku: "heh" sneering at her pathetic mastery over the quirk...then up comes Nejire and the rest of the big three who now had their stances ready...Dabi looking up at them 
Dabi: "are you all insane...he's the perfect monster...he can't be stopped!" 
Shigaraki: "Watch my friends...Because massacres like this are rarely seen...even by villain eyes hehehe" 
Izuku: "HEROES, VILLAINS, ONE AND ALL...BEAR WITNESS!!!" Breathing fire into the sky