Full Power!!

Japan's broken streets are being combed by Grand and Turtle Neck of Ketsubutsu Academy, sweeping for anyone still unsheltered so they can be moved to their school. Mid patrol a warning comes through from the Daina Police Station: one of the convicts Tomura's crew turned loose has surfaced nearby, and every hero in the district should wrap up fast. Another group of civilians refuses the offer, to Grand's frustration, and then their classmates Boomerang Man and Mr. Smith call in a panic telling them to take cover immediately. The escapee arrives by demolishing several buildings on his way down, and it is Muscular. Grand sends Turtle Neck for backup from Ms. Joke and orders her to clear the area while he holds the line.

Holding it does not go well. Muscular pins the boy without effort, bored, scanning for anyone more entertaining. Vibrate does nothing worth noticing, since his layered fibers absorb the tremors, and even a maxed out Tremoring Earth is simply buried under more muscle. Before he can finish, something out of a bloom of purple smoke smashes him across the back and hurls him into a building. Deku steps out of the cloud with Grand safe in his arms, drawn there by Danger Sense. Muscular is delighted, hungry for a rerun of their fight in the Beast's Forest, and he opens by ripping the roof out from under his target, who simply Floats clear and vanishes into fresh smoke. Smokescreen, the sixth user's contribution, is now his to use.

Deku sets Grand down with Turtle Neck, apologizes for arriving after the damage, and heads back into his own smoke. The civilians, still cold toward heroes, take the injured boy in, and one of them admits nobody wants to watch people get hurt, which is enough to get the group finally listening about evacuation. The two students are left wondering whether that really was the same kid they crossed paths with at the Provisional Hero License Exam.

Running, Deku talks with En's vestige about losing control of the smoke. En points out that the sheer stockpile inside One For All makes every inherited ability far harder to steer than it was for its original owner, and advises him to stop treating them like signature finishers. They are instruments, swapped in and out as a situation demands.

He tests the idea at once, flooding the ground with Smokescreen to blind his opponent while Float keeps him overhead watching. Muscular rockets up from below, and Danger Sense plus Blackwhip lets Deku wrap him and fling him into a river. Floating down, he demands a location for All For One and Tomura. Muscular has no idea. The two of them told him only to enjoy himself. He then complains that this careful version of the fight bores him and demands the free-for-all they had before. Deku asks whether he ever considered any other road, using his real name, Goto Imasuji. There was never anything else, the man says. He wants a life of blood, taken to the limit, regrets excluded.

His charge collapses on him. The fibers begin snapping under their own strain, weakened by the punishment Grand's Vibrate quietly inflicted, and Deku ends it immediately with a 45 percent Detroit Smash.

Muscular delivered to the Daina Police Station, Deku meets All Might in an alley. Asked about his limbs, he credits the Mid-Gauntlets, compressible red supports his mentor had shipped in from America back while crossing the country's borders was still possible. All Might warns that the prototypes will come apart if he ever pushes the full hundred percent through them. A call from Hawks comes in, with Endeavor and Best Jeanist rounding up villains elsewhere in the city. The five of them are now a unit built around the boy, hunting All For One and Tomura while sweeping up escapees. Deku slips away to resume patrol the moment All Might starts reporting his condition, unwilling to see his teacher pulled into a fight.

Earlier, when the arrangement was made, his doctor delivered rare good news. He had wrecked his arms again against Tomura, but a body that now disperses recoil properly, paired with power strong enough to reinforce itself, left almost nothing lasting from the war. Caution was still advised. All Might then told Inko about One For All and about her son being the prize All For One wants, and while he was still describing the protections planned, Izuku said he was not coming back, so the villains could not follow him to anyone he loves. He promised his crying mother he would grow stronger, and that he would return. That night he visited Gran Torino to honor Nana's request. The old man apologized for failing to stop Tomura years ago and told him not to flinch from killing if killing is what saves someone from himself, then handed over his old scarf and told him to end things with the League however he chooses. Wearing the scarf and his battered costume, Izuku walked out with the team into the dark.

Grand is overwhelmed by Muscular and rescued by Deku, who unlocks Smokescreen from the sixth user En and learns to treat the inherited Quirks as situational tools rather than finishers. He defeats Muscular with a 45 percent Detroit Smash after Grand's Vibrate weakens the villain's muscle fibers.

All Might supplies the Mid-Gauntlets and confirms the five person team of Deku, All Might, Hawks, Endeavor, and Best Jeanist. In flashback, Izuku tells Inko he will not return home, and Gran Torino gives him his scarf along with permission to do whatever ending the League requires.

The first episode of the Dark Hero arc, adapting Chapter 307 through Chapter 309. It aired in Japan on February 11, 2023, with the dub on February 25, keeping Ours and North Wind.

Two changes stand out. The manga's visual of Izuku picturing his borrowed Quirks as physical implements is dropped, and the doctor modeled on Mario has his face withheld here, only appearing later in Episode 155.