Overhaul: We finally succeeded
Chrono:yeah
Overhaul:it's not like the incomplete drug that only took a day or two to recover from. We started with preserving the effects of the factors separated from Eri's body, and it's taking a long time since then.With this we can completely annihilate someone's quirk.

He lifted a small box that contain the complete serum of the drugs that destroys quirk.

Chrono: however it will take too much time and money. It's taking a month to make enough for five bullets.
Overhaul: it's because we're doing this ourselves and these are for facilities. We will arrange for more suitable environment. Now it's our chance with all for one gone. We don't have time to dawdle.

Present Izuku POV
Mimic: Crush them all to death

Whatever's happening right now someone made mix mad the entire underground is crumbling though we kept hearing him scream.

Red hood: this guy sure likes to yell a lot where are we gonna find him.

Nightwing mind: the fact there so many echos I can't seem to find him unless echos come from one direction and theyre only the loudest the the noise is closer so....*looks up* he's above us

Using my modified boots I jump is the walls and threw and explosive wingding

Nightwing: bombs away!

It Explorer leaving some of his body open that's when he racer took the opportunity and disabled his quirk. And he fell down not without looking that's twice in toga were waving goodbye to him.

Twice: I think will do whatever you want after all.
Toga & twice: bye!

Without noticing sir Nighteye threw a seal which knocked him out and I grabbed him.

Nightwing mind: so the league betrayed him....?

Red hood: guess that's then end of this whacky ride. Which means....

Nightwing mind: kouta..... eri...... mirio....

Koutas pov
At long last after so much running mirio and I......finally reach Chisaki and eri

Lemillion: excuse me... But can I ask you some questions...?
Overhaul: You both shouldn't have been able to get here so fast.
Robin: there's always a shortcut. We're here to rescue eri.
Overhaul:Now that you know the situation you're putting on your hero mascot? Mr. students

Both of us having flashback to our first encounter with eri.

Overhaul: back then *looks at mirio* you were pretending not to see weren't you? *looks at kouta* while you wanted to save her but had to follow orders from you're classmate and had to let her go. This girl doesn't want either of you to rescue her. To her you both are no heroes.

I balled my fist I had so much anger on many things but this...

Robin: that's a lie lemillion may have made the mistake of not rescuing her and that's what he regrets I also regret it to I'm not letting that stop me so we're going to rescue her no matter more obstacles you put we'll break through them that why we're here.

Mirio were gonna rush at them with mirio having a head start but then he felt dizzy and was on his knees

Robin: lemillion what's wrong
Lemillion: my sense of equilibrium...
???: are you sholahed

I looked up at the the mysterious voice and see a guy drinking upside down with the alcohol dripping out of his mouth disgusting

???: your legsh looks sshaky... mine're too... thash why I'm walking up 'ere... don't get closh t' me...

Robin mind: what the heck is up with this guy? I guess his quirk works when I'm close to him but is I back away that's gonna keeps us away from saving Eri I can't allow that!

Just then we both heard the sound of a gun loaded and narrowly dodge a bullets there was another guy in front of us this one looks like a plague doctor

???2: what's you're quirk
Lemillion: permeation. When activated I can sleep through anything!
Robin: my quirk allows me to shoot water from my palms

This guy make people confess any question.

???2: I was wondering where you sprung from though you *looks at kouta* since you're  small you were able to get by.

I figured by Izuku research on these guys the plague doctor was shin nemoto while the crazy drunk guy is deidoro sakaki. Nemoto kept shooting at us so mirio use his quirk so the bullets pass him I use my cape to covered my self since it's bullet proof. That's when he ask mirio a question while also using his quirk.

Nemoto:when you first encountered eri, you let it girl once because of that right?
Lemillion: that's right
Nemoto: and then you probably guessed that our plan was and regretted it. Rescue eri? You just wanted to use her as a cover to make yourself feel better right?

Mirio couldn't move his body was swaying  I had to do something so I took out one of my robinrangs and threw it but not at them on the floor near them

Sakaki: What was that's supposed to do?
Robin: this

I covered my eyes as my robinrang was a flashbang and it blinded them giving as they were blind nemoto tried to shoot me that's when mirio activate his ultimate move

Mirio: Phantom Menace

He bent in the wall and was shooting out of them punching both nemoto and sakaki he disappeared into the ground and I rushed at them with both me and mirio punching both of them knocking them out after they were done mirio and I continue forward to eri Overhaul looked behind and saw both nemoto and sakaki in the ground with me rushing at him not noticing mirio coming out of the ground going to hit chisaki but he dodge and I hit the guy in the white hood in which he let go of eri and I caught her in my arms.

Eri: Why...?you both can't be here...He'll kill you two!
Lemillion: we'll won't make you sad anymore
Robin: we'll become you're heroes.

Play the song*

Overhaul: how filthy, come back eri. Killed? How many times do I have to tell you? You break people. That's how you were born.
Eri:No...You both shouldn't...
Robin: you don't have to listen to him
Overhaul: aren't I always telling you? I have to get my hands dirty because of your selfishness. Each and every action you take kills people. You're cursed.
Robin: *growls* How can you say that to your own daughter?!
Overhaul: ha? Oh I see. That's the story I told you... I don't have any children.

He reveals that his glove has been taken off and the ground split apart. We both remember that his cork was overhaul which allows him to disassemble and reassemble things that's when the ground starting to spikes and launch us. Mary I'll grab both of us and left us in the air thanks to him using his quirk he wasn't hurt.

Robin: do you didn't care about her safety?!
Overhaul: yeah, it wouldn't have been an impediment even if she broke. If I put her back right away I can revive her. Even if she didn't keep her shape I could put her back the way she was. She should already know that first hand.

Overhaul use his quirk again and blocked our exit and launched more spikes arrows. That's when the other guy had a gun in his hand and aimed it at us Maria was still under affects by Sasaki's quirk so we had no other choice but to fight that's where an idea popped in my mind.

Robin: mirio cover us
Lemillion: k

The white hood guy shot his bullets but they couldn't see us since we here behind mirio a cape that's when they saw me use my grappling hook and I went zipping and they shot it at it but It wasn't actually me it was just my cape tied to the rope of the  grapple. That distract them from Mario to sink into the ground come back out and I want to punch the white hood guy but overhaul noticed that so he made pillars to help him dodge. But since he died she lost his gun and overhaul didn't notice but I rushed  at him giving him a straight kick to his chest pushing him back. Then he didn't realize mirio sneaking up behind I'm sending a punch he tried to touch mirio but he use his quirk to go through his hand sending the punch straight to his face knocking him to the ground. The white hood guy went for his gun but kicked him to the side in which the gun lost its bullet and mag. Mirio sink into the ground and rise back up again delivering another punch

Robin: you know chisaki between the 3 of us Lemillion and I are stronger!

Eri witness the action happening in front of her remembering what we said to her

Lemillion: we'll won't make you sad anymore
Robin : we'll become you're heroes.

Robin: we won't let you lay another finger on her! We'll take you both down at once! You've lost chisaki!

3rd person POV
Chisaki was remembering on how he join the hassaikai
Flashback
Old man:Boy...If you have nowhere else to go come with me. What's your name? Can you talk?
Chisaki: Chisaki... Kai Chisaki ...
Timeskip

We are now in the office of the old man with an teenage Chisaki

Old man: the todo gang just got disbanded. We just keep getting more and more restricted.
Chisaki:At this rate, it's only a matter of time for us. We need to be more innovative. What about the plan I told you about before. Have you given—
Old man: You're still saying daddy even after getting shut down so many times? If you turn away from the path of a human, that's the end of your chivalry, Chisaki. No one's going to follow a demon with no heart.

Flashback end
Kota POV

Nemoto:Master

Mirio and I both saw that nemoto awaken and got through the blocked exit

Overhaul: nemoto! Shoot!

He threw a small box and it open reveal small darts he grabbed it and loaded it into a gun and aimed it at me and mirio we were still fighting overhaul so he can't get the right aim that's when he got the idea and pointed the gun at Eri
(A/N: who's with me on fighting this guy for pointing a gun at poor eri)
I couldn't see her get hurt again so I rushed at her with my hat falling off that's when he pulled the trigger. A hero would sacrifice their body for someone just like Izuku sacrifice his own for me I will not let you suffer anymore eri

Flashback

Kouta: papa....mama....

News reporter: Water hose... they were wonderful heroes, but couples bright lives were cut short by a single cruel criminal.

Izuku: I'm going to save you kouta

Izuku:kouta will you accept to follow this path with me and be a hero by my side

Kouta....yes because of you I now know what makes someone a hero who teach me?

Izuku: yes you'll now will be known to the world as....robin

Flashback ends

I felt pain in my arm I looks and saw a the dart on me.

Lemillion: Kouta!

Robin: it's fine I didn't even need my quirk for this it wasn't what made me strong it was by Nightwings training he made me strong by picking myself back us that's way you're not gonna stop me Chisaki!

I threw chrono at him distracting and I rushed again giving a spin kick to his skull. He threw more spike at me some I wasn't able to dodge other mirio took them for me our stamina where running so low but we kept pushing ourselves even he tried to hurt eri we took the pain for her as well.

Robin: is that's the best you can do... come at me with everything you got!!!
Overhaul: you both want to become heroes so badly? To save eri badly Robin? It's all a filthy disease of our time. I'll fix guys like you. With Erie's power
Lemillion: Nighteye...
Robin: Nightwing...
Lemillion & Robin: everyone! Chisaki!
Overhaul:I thought you both knew I threw that name away!

Just then the wall cracked and it exploded and behind the smoke came Izuku....

Robin: about time.....you made it.....

To be continue....