Before Izuku can react and stab Overhaul with his finger snakes, the villain grabs both Shin and Rikiya by the shoulders. The room is filled with the sound of molding flesh and visra as what seems to be a light emanating from hell itself opens underneath where Overhaul once stood. Both Shin and Rikiya are reduced to blood which is drawn into the light behind the desk. Izuku can make out a figure forming inside of the light and it's far bigger than anything he's ever seen. The combined fusion of Rikiya, Shin and Overhaul creates a massive Kaiju destroying the room they're in and collapsing the ceiling. The sheer size of the Overhaul kaiju is astonishing and Izuku has to make a break for the now crumbling door to escape getting crushed. Nighteye and Aizawa were already outside the room and were then grabbed by Izuku and pulled into his storage quirk. Izuku himself charges up One for All and jumps through the roof heading to the surface. Getting to the street he sees the heroes and army looking in fear of the creature behind him. Rising from the collapsing street is an amalgamation of flesh, bone and pure evil. A large muscle exposed arm reaches out of the pit followed by several more. They press down into the street hoisting the center mass of the kaiju from the underground. It's large slightly humanoid torso being held up by it's 4 sets of arms lurches out of the ground. A head in the shape of a raven leers down at them before opening its mouth revealing Overhaul attached to it by his waist. The torso of this massive creature shows exposed bones of the creature's rib cage and spine.

"You wanted a monster and you have one now All for One! Everything you see here is going to be destroyed and it will be all your fault. Once every single person in Mustafu is dead I'm going to rip that quirk from you and use it to purify this disease ridden wasteland!" Overhaul declares in an almost demonic sounding voice.

"You won't lay a hand on a single person. This is where it ends Overhaul!" Izuku responds, furrowing his brows as his face contorted with anger and rage.

His arms explode with black fire, his eyes change to the same color of blood. The air around him warps with electricity as he charges his max power with One for All. He tries to calm his mind to keep from losing control over All for One and going on a rampage. He only has one target and there's no way he can miss a target bigger than the broad side of all the buildings they are surrounded by. Overhaul wastes no time slamming his arms into the ground launching spikes from the asphalt towards the military and other heroes on the ground. Izuku manages to almost warp in front of them using his mobility quirks and absorbing them into his storage quirk. Overhaul isn't able to track where Izuku himself is but the green streak of light behind him is an indicator of how fast he's moving. By the time the spikes reach the ground all the heroes in the immediate area have been warped into Izuku's storage quirk and to safety. The military retreats down the street opening fire on the Kaiju aiming for Overhaul's exposed body. The kaiju closes its mouth to protect the host but also blinds him at the same time.

Overhaul opens the beak of the kaiju to attack the military but is caught under the jaw of the Kaiju by a thunderous attack. It's sent hundreds of feet into the air in less than a second, the strike was so powerful it nearly caused the head of the kaiju to come detached from the rest of the body. Once airborne, Overhaul has nothing to use against Izuku aside from his own biomass and Izuku intends to use it against him. Wings sprout from his back along with the shoulder jets he stole from Hood, he once again lunges up from the floor taking to the sky. Mid air he starts firing finger beams at the beast aiming for its joints trying to cauterise the flesh not allowing it to move. Overhaul uses his quirk on himself repairing the damage dealt to him and then trying to punch the green rocket heading right at him. Izuku activates another quirk of the female high end noumu that was at the facility, his fingers become meter long talons and he slashes through the arm of the Kaiju as it tries to strike him. Two of the fingers fall off from the slash and a long scar opens up along the forearm of the main arm. One of the other hands on his back lerches around to swat at him but misses as Izuku changes course aiming for Overhaul himself.

Overhaul has to lean back in the beak as the taloned hands almost slice off his head as Izuku makes a very close pass. A small cut opens on his neck being evidence of how close he was to losing his head. In anger Overhaul slams the mouth of the kaiju down, catching Izuku by the leg and then uses its arms to grab the All for One holder. "You actually tried to take my head off! Hahahaha! Looks like you're becoming more like your father the longer we fight. Let's put those regenerative quirks to the test shall we?!" Overhaul shouts using its arms to crush Deku in its palm. Deku lets out a pained scream as overhaul laughs and then throws him back to the ground. The resulting impact created a large crater, causing a small earthquake around that region of japan. The impact left him dazed for a moment as the regenerative quirks repare his body. He sits up and shakes his head from the shock of the impact before looking up at overhaul who's still falling to the ground. With the anger of everything Overhaul has done to Eri swirling around his mind. Izuku loses control over All for One, the irises disappear from his eyes only showing the whites of them. An aura of malicious intent forms around him as the very light seems to pull from the air.

Overhaul slams into the ground crushing a building that had already been evacuated, and sits back up to try and attack Izuku. When he lays eyes on him however, he freezes. As if every atom in his body is petrified. No matter what he does or tries he can't move or even look away from the abyss that has enveloped Izuku. The abyss known as the scourge of man, the thief of quirks and the blight on the history of all quirks. It was like staring into a black hole, it was a void of nothingness but that nothingness didn't last long. It was soon replaced with unbridled terror, as if fear itself took a human form and was now staring back at him. "Wha-What is this?! What are you?! What is happening?!" Overhaul says in a fear stricken voice. Izuku says nothing as he wordlessly starts to float in mid air. Like that of his own father against All Might, Izuku floats as if he was a hanged man staring down at overhaul with a cold expressionless face. "Like this feeling Chisaki Kai? This was a nifty little party trick All for One pulled in kamino. I'm gonna call it, Frightful Presence. So... How does it feel? This overwhelming power, its girth? Its hunger? This power will be the end of all evil. Of all suffering. But most importantly the end of You." Izuku says in a very reminiscent tone of his father towards All Might at Kamino. "It should be becooth me to tell you what became of that precious little ball of innocence that is Eri Midoriya. She is under my care now, and you. Won't live to see the follicles of hair growing from the head that you tried to warp and that you destroyed. Allow me to show you the truest definition of Despair, then and only then... Will you have my permission to Die." Izuku says floating higher into the sky, he tilts his head to the right as he opens his left hand towards the sky. A massive ball of energy from his several emitter quirks forms in his hand going from a pink color to a dark and ominous purple as it gets larger and larger. "But first. You're going to feel as helpless as she did when you were torturing her."

The impact of the energy sphere was so fast Overhaul couldn't even register how quickly it moved. A perfectly circular hole was now in the center of his chest that same orb slams into the ground creating a large explosion scorching the back of the kaiju. Overhaul screams in pain as the All for One user attacks. Once again he's struck and sent into the sky, the once green aura around Izuku having turned black and red. "Why can't anyone... LOOK AT THE BIGGER PICTURE!!!" Overhaul shouts as he deconstructs his body creating a vortex of gore in the sky as it forms overly large limbs on his body. "All you hero pretenders are the cancer in this society and no one realizes that!!!" Overhaul screams trying to punch Izuku but only for him to zip past him taking off the arm that Overhaul tried to strike him with. From above him Izuku rears back a punch with Eri's horn on his head glowing a bright golden color. In the sky hundreds of fists appear before connecting with Overhaul's body. Each strike blowing off more and more flesh from the Kaiju. Overhaul tries to recover from the attack looking up at Izuku to try to counter but is met by the hero with a raised fist his eyes both showing their brightly glowing green irises through an angered expression. The punch connects with Overhaul's actual body sending him flying to the ground back to the crater that Izuku had originally made when he was struck.

Landing on the ground, Izuku creates the talons on his fingers again walking up to what's left of Overhaul on the floor. He grabs the villain by the collar and hoists him into the air moving his right hand behind him with the talons as sharp and as long as he can make them. "Do... it... You'll become... the villain you're meant to be." Overhaul says through an exhausted voice looking deku in the eyes. Izuku raises his hand even more as if to strike but he stops himself and drops Overhaul to the ground and retracts the talons on his hand. "No. I'm not a villain, I won't kill you." Izuku says exhaling deeply. "I knew you couldn't. You're weak." Overhaul taunts, "That's where you're wrong Chisaki, true power is having the justification to kill but not taking a life." Izuku responds before turning his back and walking away from him. Izuku reopens the storage quirk allowing all the pros he rescued out of it.

"You did it Deku-kun! I knew you could!" Ochako shouts seeing the defeated Overhaul on the ground.

"Yeah.. I did didn't I-" Izuku is cut off a by a gunshot and bullet exiting from between his eyes, his body regenerates the wound and he whips around with all his quirks active to face overhaul who is pointing a smoking revolver at Deku as a last attempt to kill him. Izuku lurches forwards to decapitate him but Aizawa cancels out his quirk causing Izuku to whiff the attack in the air. The revolver is snatched from Overhaul's grip by Eraserhead's capture gear.

"Go to the others, make sure they're alright. I will handle this." Aizawa says coldly before drawing his pistol from his back. "You just blew your last chance at mercy you know that right?" he asks, walking up to him and clicking the safety off the pistol.

"I don't want your mercy you filthy hero! I want this society cured! Killing him was the only chance to keep the blight from spreading!" Overhaul declares trying to shimmy away from Aizawa using his arms.

"He did say you were leaving here dead or alive. Would have rather you walked out but instead." Aizawa says stepping on Overhaul's chest and putting the barrel of the desert eagle to Overhaul's forehead. "You had to go and leave a mess." He replies before pulling the trigger.

"Why didn't you let me do that!? He fucking shot me!" Izuku shouts angered with what Overhaul did and with Aizawa looking at him with a rather irritated stare.

"You held your anger before when it was about Eri. It wasn't worth you losing to that demon in you over someone that can survive something like that." He walked away with Izuku still angered to no end about this. The green haired boy walked over demanding answers from his teacher before being stopped by Nighteye.

"He did what he did to ensure a future I witnessed. In that future, you didn't kill Overhaul and things turned out far better because. If you were to end the villain's life yourself, a darker future would have happened because of it." Izuku wasn't exactly happy hearing this with Nighteye trying to reassure him. "I understand your frustration and I commend your efforts with stopping when the moment of truth happened. No matter what Overhaul said, you aren't your father. You are no villain. You are a hero Deku and you've proved that today. Unfortunately, heroes will have to kill when things happen like that. But knowing when killing out of emotion and killing out of what has to be done is needed as well. What Eraser did was as a way to keep you from falling down the former path. If he didn't step in, that kill would have haunted you because you chose to let your demons win. The ones you have no choice to do hurt, but the ones you could've done differently hurt more."

Izuku thought about this as they walked out. Before they made it to the surface, Izuku gave his teacher a single comment realizing that Nighteye was right. "Thank you. I don't think I would've been able to handle that happening."

Aizawa didn't look at Izuku while answering him. "You're a good kid all things considered. You'll also make a great hero and a good parent to Eri. Just keep your head up and think things through before you act." Izuku smiled at this with a smirk grazing Aizawa's face. 'You're on your way kid. Just keep going and you can prove those that are scared or question you wrong.'