Chapter 405: The Final Boss!!

All Might asks the Nighteye in his head whether this was not supposed to be the hour of his death. The answer is that the prophecy claimed his dream, not his life, and that the reshaping of fate left his promise to keep living for Izuku's sake unbroken. He protests that the old mentor is meant to die once the torch changes hands, and Nighteye jabs that he has read too many comic books, prompting All Might to marvel at what his own hallucination is saying. A hero is still a human being, Nighteye adds with a smile, and humans do not die that obligingly.

Dynamight blasts himself onward with All Might in tow and sets down on a rooftop. Viewers of the broadcast scramble to place him, some recalling the boy from the Sports Festival and the kidnapping by the League, while Katsuma and Mahoro recognize him instantly. All Might asks whether he is all right and gets the question thrown back at him.

A gush of blood follows, and Edgeshot emerges from Dynamight's body thinned to the width of a thread, saying the question is his to ask. He explains that the expelled blood should bring relief, and that he used himself to tie the ruined organs and bones back together with knots in the Hidden Hakamada Style, so the repairs will hold. Movement, though, will still cost him, because the body needs rest. Dynamight thanks him for the return trip.

Edgeshot refuses the credit. All he did was hold the pieces together; restarting the heart and lungs did not amount to restoring life. With Thousand Sheet Pierce and Zenith consuming his own lifespan, he had reached his limit when he noticed a single bead of sweat racing through the bloodstream, produced moments before death. What brought the boy back, he says, was the power the boy himself built.

Asked about the glowing child, All Might confirms that this is All For One, the opponent he intended to face. Unable to move, he has Katsuki hold out an arm and straps the surviving remnant of his gauntlet onto it for support, the piece named Great Explosion Murder God Dynamight, wishing aloud that he had more to give as he collapses. Dynamight answers with a grin.

All For One starts after them both, then checks himself, deciding that One For All and his brother come first, which means overwriting Tomura's will with his Quirk and his own being. His blood boils as he recalls the vestige failing to seize the body, and with the faces of every stubborn hero he has fought flashing past, he wonders how the gears slipped so badly when the wind was supposed to favor him. Dynamight lands in front of him proclaiming himself the final boss, which drags up another flash of the Second User, and unloads an Explosion right in his face, saying that One For All failed to keep him buried and that the two of them will finish the job.

Dynamight lands safely on a nearby building with All Might.

Edgeshot emerges from Dynamight's body and reveals that he knotted the boy's organs and bones back together, and that the thing which actually brought him back was a single explosive bead of sweat.

All Might hands Katsuki the one surviving fragment of his armor, Great Explosion Murder God Dynamight, to brace the arm.

All For One refocuses on Tomura and One For All while the defiance of the heroes drives him further into madness.

Dynamight confronts All For One directly, opening their fight.

Horikoshi's four hundred and fifth installment fills 15 pages of the fortieth collected volume, placed within the Final War arc.

It ran in issue 48 of 2023, published on October 30, and is adapted as Episode 162 of the anime.

Fandom trivia points out that nitroglycerin is used medically to dilate the vessels of the heart during heart failure or severe chest pain, a parallel to how Katsuki is revived. The chapter starts the Dynamight versus All For One bout.