At the crossroad, Ryukyu orders Akari and Nejire to blast her and Rikiya onto the ground with everything she has.

Akari: Here goes nothing. Ready Nejire-chan?

Nejire: Ready!

Ochako releases her Quirk's effect as Akaria and Nejire blasts Ryukyu and Rikiya with their Quirks.

BOOM!!!

The combined weight of Ryukyu and Rikiya along with the force of the two girls' sparks and shockwave is enough to make the crossroad collapse, causing Ryukyu's group along with Rikiya to fall down into the Shie Hassaikai's underground where they land in the middle of the battle between Izuku, Mikoto, and Kai Chisaki.

Deku: Uraraka-chan?! Tsuyu-chan?!

Mikoto: Girls?!

Uraraka: Wait...a minute...

Luna: What is it?

Uraraka: If Deku-kun is there...then who is...?

Ochako and Tsuyu are shocked that the Izuku they saw above was.......

Niko: Hi~~~!

Toga: *Waves*

Luna:...

Mio:...

Zoe: We been tricked...

Toga Himiko, Niko, Juurou, Twice, and a copied version of Atsuhiro Sako are above ground.

In the underground, they let the copy out, then Jin made copies of himself to dig a hole to the surface where Toga transformed into Izuku to trick Ryukyu's group.

Twice is glad that the Heroes showed up today as it allowed them to identity the "core" of Chisaki's operation which is Eri and they plan to snatch her. Twice orders the Atsuhiro copy to go and snatch Eri.

Everyone couldn't believe it. The League of Villains had manipulate the Heroes into taking down Overhaul.

Atsuhiro goes to snatch Eri which surprises Ryukyu's group.

Mikoto: Eri-chan!!! *Jumps*

Mikoto jumps in the air and went after the villains.

Destiny: Class Rep!

Izuku tells Ochacko that he is leaving Sir Nighteye to them as he goes help Mikoto to rescue Eri.

However, Chisaki prevents Izuku and Mikoto from reaching her with a rock pillar and he grabs her.

Chisaki is annoyed with everything being ruined and seeing the hole, an opportunity of escape, prepares his escape by reconstructing a large and long rock pillar to take him to the surface.

Izuku and Mikoto refuses to let Chisaki get away. As they head for the surface, Mirio Togata's cape caught by debris, which Chisaki finds sickening. By instinct, Eri grabs Mirio's cape after remembering Mirio's kinds words.

"A hero uses his cape to wrap up a hurting girl whose suffering and in pain!!!"

Eri:...

Suddenly, Eri begins emitting a strange energy which starts affecting Chisaki.

Mikoto: Whoa...

Deku: Eri-chan...

Overhaul: ERI!!! WHAT ARE YOU DOING?!!

Eri's quirk...has awaken...

Eri is later revealed to be the granddaughter of the Shie Hassaikai's boss, whose daughter cut ties with them after a dispute over her marriage.

Another factor that caused the boss's daughter to disassociate from the group is that Eri caused her father's death after he touched her and he simply vanished into thin air.

The boss reveals to Chisaki that Eri has a strange Quirk that did not resemble anything from her family lineage and believes it is a genetic mutation.

The boss does not know much about how Eri's unique Quirk works but due to it resembling Chisaki's Quirk is the reason why he has asked him to take care of Eri and investigate her Quirk. During investigation, Chisaki starts thinking that Eri's Quirk is on a completely different level from his restoring or repairing and hypothesizes that Eri's unique Quirk can rewind genetics...in short terms, Chisaki finds Eri's Quirk to be terrifying.

In the present as according to his hypothesis on Eri's Quirk, Eri's Quirk begins activating which causes Chisaki and Shin Nemoto to split apart, returning Chisaki and Shin to normal.

Today was the first time Eri tried to escape but had given up hope due to thinking there was no escape from Chisaki.

Robbed of her freedom, experiments were made on her body day in and day out. Eri's fearsome Quirk caused her to blame herself her being born with this strange Quirk and resigned to being "cursed", accepting her fate.

However, Mirio's words shook Eri's heart to the core and could no't bear to see others hurt for her sake; she was further shocked that everyone refused to give up on her, which caused her to start developing new feelings, feelings that compelled her to save them, which allowed her to activate her Quirk's power.

With that, Eri rewind Overhaul to his normal form.

In the past, Kai Chisaki learned from the Boss that Eri's mutation erased her father and made her mother abandon her.

The Boss had asked Kai to study Eri's power because he thought they were similar. However, Eri's curse is something entirely different. Kai discovered that this ability is a Quirk that rewinds.

Eri rewinds Overhaul back to his normal form before he fused with Shin Nemoto. She grabs onto Lemillion's cape and jumps out to embrace Deku.

Eri: Mr. Deku!!!

Determined to rescue Eri, Deku jumps through the air and reaches out to her until she finally leaps into his kind arms.

Deku: I promise to never let you go again. This time...I will save you...

Mikoto: *Smiles* Izuku...thank God... Eri-chan is safe...

Izuku grabs Mirio's cape which Eri is also holding onto.

Eri embraces Deku as he tries to finally rescue her.

But first...they needed to deal with Overhaul....

Izuku Midoriya grabs hold of Mirio Togata's cape, reels the cape in and grabs hold of Eri, promising her that he will not let go of her this time. Infuriated, Kai Chisaki demands that Izuku and Mikoto hand Eri back to him and charges at him.

Overhaul: GIVE HER BACK!!!!!!

Mikoto: Brace Yourselves!!!

Mikoto uses the snow shield to block Overhaul's attacks. But not for long...

Izuku isn't able to move well suspended in mid air. However, Izuku vows to not let go of Eri no matter what and remembers Mirio's question of what Hero he wants to be...

He wants to be a Hero that wipes everyone's worries aways, always wins and saves everyone. Mikoto was the first person to help him see that...and now...

Filled with utter determination, Izuku unconsciously activates One For All 100% and prepares to attack Chisaki with a kick, while Chisaki launches reconstructed stone pillars at Izuku.

Overhaul: RAAAAAAGH!!!!!!

As Chisaki's stone pillars begin to ensnare him, Izuku l disappears and the ceiling above them collapses as a shockwave ensues.

The collapse of the ceiling and the resulting snow wave was caused by Mikoto launching himself out of the basement using icy wind pressure.

Izuku himself realizes as he traveled through the air at high speed using One For All 100%'s generated wind pressure, similar to All Might's New Hampshire Smash and in the process smashed himself out of the basement. However, Izuku's legs are completely broken as a result.

Back in the Shie Hassaikai's basement, Ryukyu's group are in confusion as to what occurred.

Destiny: What's happening...

Luna: W-What in God's Name is that thing?!

Akari: Is that...Overhaul...

Zoe: If that is him...we could be in big trouble...

Mio: *Whimpers*

Ryukyu: Stay strong girls...

Akari: Yeah! Right now let's gather up all the information we need an the Shie Hassakai and get out of here...

Nejire: Right Akari-chan!!!

Chisaki gets up and is injured of the shockwave caused by Izuku's One For All 100% and the snowwave caused by Mikoto.

Having become desperate in getting Eri back so that he can realize the Shie Hassaikai boss's ambition,

Chisaki uses his Quirk on Rikiya Katsukame and fuses with him.

Ryuko Tatsuma prepares for battle, but a badly injured Sir Nighteye, who is being tended to by Tsuyu and Zoe, eases Ryukyu's worries as Chisaki is going to pursue Izuku and is intend on not only getting Eri back but murdering Izuku as well.

Uraraka plans to go to Izuku's aid, but falls down due to her stamina being drained courtesy of Rikiya's Quirk.

Uraraka:...

Destiny: Everything alright Uraraka-chan?

Uraraka:....Peachy...

Despite Sir Nighteye's prediction, Ryukyu refuses to let Chisaki go after Izuku. However, Sir Nighteye convinces her that her group cannot hope to defeat the newly fused and empowered Chisaki. Ochako refuses to stand by and do nothing.

Sir Nighteye: Asui...

Tsuyu: Tsuyu-chan...

Sir Nighteye:....Please...tend to Mirio...
Uravity, Aqua, and Ryukyu...help me get to the surface.

Luna: No problem Sir Nighteye. We got this...I hope...

-Plus Ultra-

Surprisingly, Izuku manages to land on the ground safely despite his legs being broken. However, Izuku realizes that his legs are not broken and have in fact being healed, surprised that despite using One For All 100% his body along with all his injuries have been healed. Izuku realizes that his healed body is thanks to Eri's Quirk ability. Suddenly, Izuku begins feeling the immense recoil of One For All 100%.

Overhaul willing to bring back Eri...

Chisaki appears and states that Eri has unlocked her power but doesn't know how to stop it and launches reconstructed pillars at Izuku to which he dodges. The newly fused Chisaki appears, looking similar to a stone dragon.

From the dragon's maw, Chisaki appears and reveals that Eri can rewind humans and depending on how she controls it, she could revert a human back to a monkey or even to nothingness.

Overhaul: Her quirk is a curse amd that holding onto Eri is dangerous, which is why I'm demanding that you both return Eri to me!!! Because only with his Quirk can he stop Eri's cursed Quirk.

Eri:...

Deku: No.

Mikoto: Never. Who the heck do you think you are to decide someone's future because of their quirk?!!!

Both boys vehemently refuses to hand back Eri and will hold onto her no matter what.

And Mikoto is willing to be their shield to make sure that never happens.

Having experienced Eri's Quirk, Izuku sees that the moment his legs broke Eri reverted them back to normal before he could experience any pain and thinks that Eri's Quirk is a kind, gentle Quirk contrary to Chisaki's thoughts, which shocks Eri.

Eri: (My quirk is...gentle?)

With Eri's help, Izuku uses One For All: Full Cowl - 100%.

Understanding that Eri's Quirk reverts any pain and grievous damage back to normal at blinding speed.

Izuku decides that he doesn't need to hold back since all major recoil and damage accumulated by his Quirk will be continuously reverted and healed thanks to Eri's Quirk, therefore not needing to worry about turning into nothingness.

Izuku: Eri-chan..if it's possible...will you lend me your power...

Then going all out, Izuku activates
One For All: Full Cowl: 100%.

"Exceptional Abilities" is a never before seen mysterious mutation that quickly spread among people.

According to one theory, it was an unknown virus that was spread throughout the world carried by mice and is believed to be the origin of Quirks.

However, there is no clear evidence that backs up this theory.

In the present, Overhaul claims that neither Izuku, Mikoto, nor Eri herself understands the true power behind Eri's Quirk and through extensive research.

He was able to successfully extract Eri's power and bring it to its pinnacle; the result is the Quirk-destroying bullet, which has the power to extinguish one's Quirk Factor and return them to normal.

However, Overhaul was then sent flying by both Deku and Mikoto.

Chisaki reconstructs the surrounding area and attacks Izuku with stone columns. However, Izuku's greatly enhanced speed thanks to One For All: Full Cowl: 100% enables him to dodge with ease.

Izuku delivers a kick packed with massive strength and sends Chisaki flying into the air. Mikoto slams a powerful ice punch onto Chisaki's head rendering him more damage. Izuku feels that Eri's power is getting stronger due to her being unable to control it, similar to his inability to control One For All when he received it.

Himiko Toga and Niko witnesses Izuku's and Mikoto's strength and is mesmerized by it.

Niko: So dreamy~~~!

Toga: IKR.

Juurou: Oi. Are you two done day-dreaming. Have you seen where the Atsuhiro Sako's clone wner...

Twice: Yeah...That's what I want to know...

-Meanwhile-

In the Shie Hassaikai's basement, the Atsuhiro clone is held down by Ryuko Tatsuma, who sends the weightless Ochako, Luna, and Sir Nighteye to the surface.

Ryukyu: Both of you. Get Sir Nighteye to an ambulance.

Luna: Yes Ma'am!

Uraraka: Let's hurry Luna-chan!

Luna: Alright...

Uraraka: (Deku-kun...Miichan... Please be safe...)

Meanwhile, Chisaki has been sent straight into the air by Izuku's great strength, having been injured as a result.

Mikoto: It's time we finish things here...

Deku: Right!

Mikoto: Are you ready...Inari...

Overhaul's eyes went wide...did he just say...

Inari: *Appears* Yes...I am ready...

Inari appeared out of nowhere while Overhaul stared in shock. That boy...He was supposed to be Eri's vessel. How did the heroes have him...unless...his subordinate failed in the kidnapping.

Overhaul: *Rage* No....

Mikoto: Then please...led me your power...

Inari didn't say anything as his a dark blue glow surrounded the two. Snow and flames combust everywhere. Mikoto felt an powerful surge spread through him.

Unlike Eri, Inari looked back at Overhaul. The child show no fear but anger.

Inari: This is for mother and father...

Inari then disappeared then reappeared in Geysis' arms.

Geysis: That was real reckless you little rut...

Inari: I know...but... isn't that what heroes do...be reckless...

Geysis couldn't help but laugh. Ironic isn't it...

Geysis: I suppose you... after all...I can't believe Yukimura had planned all this from the start...

The mysterious aurora surrounded Mikoto turned very powerful as snow came to life once again charging at Overhaul at fast speed. Splitting his reconstruction armor in two.

Overhaul: No...How...

Izuku jumps towards the airborne Chisaki who has healed his injuries by reconstructing himself and tells the fake Heroes to stay out of his way as he slashes at Izuku with one of his claws.

However, Izuku evades with ease and knows that Chisaki can repair himself with his Quirk through disassembling and reassembling at a fast rate, but he plans on using the great power of One For All: Full Cowl: 100% to close that gap and beat him before he gets the chance to recover with his Quirk.

Izuku charges towards Chisaki and starts pummeling Chisaki's monstrous stone body, shattering it as Chisaki is unable to counter attack.

Deku reaches Chisaki's own body and pummels away. Izuku questions that if he cannot save one little girl right in front of him, then he can never become a Hero that saves everyone.

Ochako, Luna, and Sir Nighteye have reached the surface and bear witness to Izuku and Chisaki's battle.

Ochako questions Sir Nighteye's vision about Izuku and Mikoto dying.

Sir Nighteye replies that it is the unchangeable future he saw but is surprised that events are playing out differently.

Luna: So that means...

Ochako: *Smiles* They're not going to die...not yet...not by a long shot...

Luna: Thank Goodness...

Deku and Mikoto reaches Chisaki and both of them punches him in the face.

Deku: FULL COWL!!! 100%

Mikoto: MYSTICAL SNOW!!!!

With enough force that not only sends Chisaki reeling but also breaks off his plague mask.

They did it...

Both boys had changed the future into a victory...

They have won...