Nighteye Squad vs. Kai Chisaki & Hari Kurono

Nighteye Squad vs. Kai Chisaki & Hari Kurono is a battle fought between Sir Nighteye's group including Sir Nighteye, Eraser Head & Deku against Shie Hassaikai members Overhaul & Chronostasis.

Prologue
Following Mimic's defeat, Nighteye's squad regroups and interrogates the villain. The Police Force are concerned about Himiko Toga and Twice lurking about. They ask Irinaka to fix the labyrinth but Eraser Head explains the Quirk-Enhancer has worn off.

Still recovering, Rock Lock tells the group to keep after Eri while the Police track the League of Villains. Rock Lock is too injured to press on and says he will look after Irinaka. He encourages the rest of the group to make one last push to finish the mission. Inspired by all those who've fought valiantly so far, Deku promises to rescue Eri no matter what.

Deku, Eraser Head, and Sir Nighteye race through the underground passageway. They pass Deidoro Sakaki's unconscious body and burst through the wall onto Overhaul and Lemillion's battlefield.

Battle
Deku kicks through the wall using a One For All: Full Cowl - Shoot Style Smash and immediately attacks Overhaul. He punches Overhaul in the arm and sends the villain falling back away from Mirio and Eri. Eraser Head tells Sir Nighteye to secure the girl while he and Deku hold off Overhaul.

Sir Nighteye embraces Mirio and Eri. He quickly realizes that Lemillion defeated three villains and beat up Overhaul. Sir Nighteye tells his pupil he did an outstanding job saving the girl. Eraser Head erases Overhaul's Quirk and rushes him with Deku. Gravely aggravated, Overhaul shouts for Chrono to wake up. During the earlier skirmish with Lemillion, Overhaul healed Chrono's head injuries after the hero threw him.

Eraser Head anticipates the attack and pushes Deku out of the way. Chrono's Quirk activates, extending his hair to a point that cuts open Eraser's arm. As a result of Chronostasis's Quirk, Shota's movements are slowed down significantly. He can't stop himself from blinking and Overhaul's Quirk returns. The villain creates a fissure of spikes to attack Deku.

Refusing to allow the heroes to foil his plans, Overhaul asks Nemoto to help him. He figures Nemoto would glad to give his life to the cause. Overhaul disassembles his own body and Nemoto's before fusing them together to grant Overhaul a new, stronger, and more monstrous form.

Taking an interest in the ability to erase Quirks, Chrono captures Eraser Head and escapes the battlefield. By fusing with Nemoto, Overhaul recovered from his injuries and regained his stamina. Overhaul taunts Lemillion once more, announcing to his allies that his Quirk has been erased for good.

Overhaul rushes at Sir Nighteye, who's protecting Mirio and Eri. Deku breaks off a spike and throws it at the villain from above. Overhaul uses one of his extreme limbs to disassemble the spike and reassembles it as multiple spikes to attack Deku. The young hero uses his Iron Soles to break through the attack, but Overhaul isn't impressed.

Sir Nighteye hits one of Overhaul's monstrous arms with a Hyper-Density Seal. He rushes into the battle and tells Deku to switch places with him. Sir knows that it took the Shie Hassaikai a long time to develop the Quirk-Destroying Bullets. Overhaul admits he meant to keep that a secret and Sir replies that Overhaul was so scared of Lemillion he had to use one of his valuable bullets.

Overhaul reassembles his destroyed arms and slashes at Sir Nighteye. The hero evades and Overhaul notices his movements are similar to Lemillion's, leading him to surmise that Sir Nighteye is his teacher. Nighteye strives to protect Mirio and fights to keep him and Eri out of harm's way. Deku carries Mirio and Eri to safety, kicking a hole in the wall to retreat with them back the way they came in.

Nighteye peers into Overhaul's future to give himself some hope about the mission. However, he pushes his own body past its limit and ends up skewered by Overhaul's spikes. Overhaul pursues Eri, forcing Deku to leave her to Mirio. Deku charges up more of One For All and stomps on the ground to break apart the incoming spike attacks from Overhaul. His body aches with great pain, but Deku can still move as he pushes One For All to 20%!

Overhaul claims that the heroes efforts are fruitless and that all of them will die. Deku claims that if that's fate, then he will simply have to defy it. Deku uses the unmodified pieces of the ground as a base for his advance. Overhaul sends multiple pillars at him and Deku narrowly dodges. He can gauge the timing of Overhaul's reassembly but it's still to fast to evade.

Deku kicks into the ground and the shockwave breaks apart the other pillars. Deku knows Overhaul isn't going to let up and tells himself to endure the pain until victory is at hand. Overhaul reaches for Deku with his monstrous arm and Deku jumps above him. Deku repels himself off the roof of the cave and summersaults at the villain. He knows that Overhaul can heal himself so he tries to end the battle with one heavy blow to the head. Deku finishes his flip with a downward kick, attempting hit Overhaul with a new Super Move: Manchester Smash.

Overhaul uses his extra hands to move out of the way and comments that Deku's moves are too straightforward compared to Lemillion and Nighteye. Overhaul manipulates two pieces of debris and wedges them into Deku's arm and leg. He commends the aspiring hero for his persistence and compares it to Lemillion's. Overhaul calls out Eri and she rushes back into the cave claiming that she never wanted any of this.

Eri agrees to come back on the condition that Overhaul heals everyone. The villain simply replies that Eri has always tried to take the pain for others and because of that, she's unwanted. Izuku unlodges the spike from his leg and crushes it while loudly proclaiming that no one will die today and that he will save Eri. Then suddenly, Ryukyu's group crashes through the roof with Rikiya Katsukame in tow.

Aftermath
In her dragon form, Ryukyu slams Katsukame on the ground. Deku asks Uravity to look after Nighteye and rushes toward Eri. Suddenly, spikes rise from the ground and impede his path. Overhaul creates a giant pillar and grabs Eri. He raises them both toward the newly formed hole in the roof.

Deku jumps and reaches out to Eri. Eri subconsciously grabs Lemillion's cape as it flies through the air. She thinks of his kind words and awakens her power. Eri touches Overhaul and rewinds his body to before he fused with Nemoto, separating them both. Desperate to save everyone, Eri leaps into Deku's arms.