Future Izuku pov
A few days after discovering the shocking truth... While the pro heroes that teamed up with sir nighteye were pinpointing the location of the young head of shie Hassaikai, chisaki, and eri, we were on standby. And we were absolutely forbidden to say anything about our work studies. Kirishima, and y/n. Uraraka, and asui. Everyone who was there at that time would be part of the operation to save eri. Y/n seemed a different person. I should've known that the weight of all of the things that happened would weigh on him. He constantly overworked himself and stopped hanging out with anyone. This affected him more than others.
Y/n pov
Y/n (thoughts): I have to grow stronger to save eri. Even if I die to save her. That is my role, as the older brother. The job I've been neglecting.
Mina: snowy?
Y/n: h-huh?
Mina: are you okay?
Y/n: yes, why wouldn't I be? (chuckle)
Mina: you haven't been acting normal. You just sit in your room all day. Usually, you'd watch tv with us, and eat with us. But now we barely see you at the dorms. You don't even talk at school. What's wrong?
Y/n:...Sorry, I can't tell you. But thank you for worrying.
Mina: just know I'm here for you.
Y/n: thank you, pinky.
...
Two days later...
*Bzzzt*
There it is!
You went down to the 1st floor (ground floor) and saw the others.
Kirishima: did you all get the message?
Uraraka: yeah.
Tsu: we did.
Y/n: finally...
Izuku:...the day we move.
...
Skipping the part where nighteye tells everyone how he found and where eri is and going straight into the attack.
8:00
Police chief: after nighteye used foresight on the Hassaikai member, we confirmed the existence of undocumented underground facilities at the head of the Hassaikai's residence. We were able to confirm that the girl we are trying to rescue is being held in one of the rooms there. Although we were unable to uncover the entire underground layout, the path the man took is the shortest route to our target, and it's the best intel we could have for searching the Hassaikai's expansive stronghold. However, even if we head there if they use their quirks freely on us, it would make the search difficult. So, we have made a list to the best of our knowledge of quirks registered to Hassaikai members. Please memorize this list.
Hero 1: it's nice to be able to pull this out, huh?
Police chief: we don't want to give them time to hide, so we want to identify and apprehend all the members as quickly as possible.
Kirishima: things are moving fast now, huh?
Amajiki: you're energetic for how early this is...
Uraraka: I'm getting nervous.
Tsu: from detective work to cooperation with the police... There's so much that I don't know.
Nejire: right? Isn't it mysterious?
Ryuku: yeah, schools don't really teach you much about things like this. I had a hard time when I first started.
Hero 2: yeah.
Kirishima: all the pros are so calm. Is it 'cause they're so used to this?
Y/n: yes, they are ready to put their all into saving eri.
Midorya: hey, I haven't seen gran torino all morning... I wonder where he is.
Sir nighteye: apparently, he cannot come anymore.
Midorya: huh?!
Police chief: it looks like the league, which tsukauchi is keeping an eye on, is on other moves. But well, we have enough people, too, so it should not impede us.
Midorya: I see...
Kirishima: maybe we can catch the Hassaikai and the league of villains all at once!
Izuku: yeah! All right!
Aizawa: hey.
Izuku: Mr-raser head!
Aizawa: I will move with the nighteye agency. Do you understand what that means?
Izuku: yes, sir!
Police chief: heroes! Things might get a little violent. If you see even a hint of suspicious behavior or resistance, please deal with it immediately! We're up against gangsters who have survived until now. Don't let your guard down and carry out your respective tasks. We will commence the operation at 8:30! All hands, move out!
...
8:30
Finally, it was time!
Police chief: once they've read the warrant, charge in! I'm counting on everyone to move swiftly.
Before he could ring the doorbell someone came out punching the door.
Villain: what do, you want? Bringing all these people so early in the morning...
Rock lock: hey, Wait! Hang on a second! Did they already notice us?
Hero 1: forget about that, let's just all hold them back together!
Villain: I feel a little more awake now. Jeez...
Ryukyu: get back!
Villian: what do you people want?!
He punched ryukyu causing a lot of smoke to appear. Once the smoke cleared ryuku was there in her dragon form and she caught his punch.
Ryukyu: anyway, we shouldn't split forces here. Ryukyu agency will take care of him. The rest of you go now, while you have the chance!
Fat gum: okay! Everyone, get in! Quickly, quickly!
Everyone ran in and began attacking the people inside.
Y/n (thoughts): wait a little longer eri, oniichann's coming!