Episode 163

A pregnant woman with white hair and spiked growths on her arm drives off a couple who ask if she is alright. The twins she carries share an umbilical cord, and the larger one, roughly five times his brother's size, strips every nutrient before it can reach the smaller. She dies by a riverbank in the rain; the bigger infant gnaws her flesh and swallows the growths while gripping his sickly sibling's hand, and floodwater carries them off. Around the same time, a glowing baby in China makes headlines, and reports of superpowers follow worldwide, some appearing as late as puberty. Filed as a disease and a new branch of humanity, the announcement tips society into open war over the definition of human. The older twin thrives in that chaos with a power that takes abilities and can hand them out, his first acquisition being the passive Spearlike Bones eaten off his mother. Anyone who gives him nothing, even attention, is a target; his brother throws a can at him to beg him to stop, gets kicked down, and is dragged away by the hand anyway, because possession is not the same as affection.

The frail one reads comics, unable to manage denser text, and says the pictures let him read a creator's hopes directly. He wants to be Captain Hero one day, and invites his brother to sit and read with him, believing that the huge hand which gripped his own on the day they were born is proof of some buried kindness. Three years later, the older brother floats down glowing, reporting that the Chinese ambassador for peace has ten million followers, that he killed him and took his light, and that he finds it strange a story like that unites anyone, especially since roughly fifty Indian children had powers two weeks before the first registered case. He points at the comics' catchphrase, one for all and all for one, admiring the Demon Lord who rules through fear more than the hero who works alone, and declares his own dream: a world that exists entirely for him. He grows into that name and that stranglehold over Japan, while his brother never submits, so All For One forces a Power Stock Quirk onto him and finally gives him a name, Yoichi, the first thing ever given to him. When resistance soldiers Kudo and Bruce spirit Yoichi through the sewers, All For One shreds his brother apart, leaving one hand in the wastewater; Kudo sees no light reflected in the man's eyes. Later, examining the hand, All For One learns Yoichi's real Quirk was too weak and malformed to detect, that it absorbed the transplanted Factor to strengthen itself, and that it activated at death. Kudo and Bruce reach the same conclusion from the other side: two Factors now share one body. All For One murders Kudo, his bloodline, and everyone near him in tears, hunts Bruce and finds nothing to take, and by the fifth user the Quirk is too strong to steal; even cut in half, En passes it to Nana. Only Kyudai Garaki's intervention saved him after All Might once caved his skull in.

Facing Dynamight, and blaming Kudo for all of it, All For One runs out of time and unleashes Omni-Factor Unleash, fusing every stored Quirk into a building-sized mass while reserving just enough to power up Tomura. All Might and Edgeshot recognize the gamble: this much output rewinds him to infancy. Dynamight holds his ground, remembers what he told Izuku about getting strong, and detonates delayed explosions built from nitroglycerin-like sweat wrapped in ordinary sweat, set off by sweat he planted in the villain's mouth earlier. The face disfigures, the stockpile crashes, and a colossal Howitzer Impact followed by a rain of blasts incinerates the mass. Hawks' vestige explains why the Factors will not obey: hatred for his own successor has eaten his control. Gripping what remains, Dynamight says the story belongs to everyone who kept him alive, and finishes it. All For One survives as an infant, still crawling for One For All, and fires a Spearlike Bone that Dynamight catches in his teeth and detonates. Rewinding accelerates past fetus, past zygote, into a mote of light that dissolves in the dirt, and Dynamight collapses with his good arm raised, telling his classmate to give Tomura hell.

All For One's origin is told in full, from the twin who consumed his brother in the womb to the theft of the Luminescent Baby's power and the adoption of a comic book phrase as his name and his Quirk.

Yoichi's hidden Quirk absorbs the Power Stock Factor forced onto him and passes to Kudo at the moment of his death, creating One For All and the one thing All For One could never reclaim.

All For One activates Omni-Factor Unleash and loses; Dynamight's delayed sweat explosions and Howitzer Impact incinerate him, and the recoil rewinds him out of existence.

The fourth episode of season eight adapts chapters 407 through 410 and aired in Japan on October 25, 2025, with the dub on November 8.

The narration is restructured. A new scene has the mother shooing away tourists, while the opening narration about her life, death, pregnancy, and her Spearlike Bones is dropped in favor of a short remark from All For One about half-remembering the day he was born. Shots inside the womb are added, removes the rats that would have eaten the infants, and drops the manga's stated time passages. It also shows the full murder of the thugs including a Quirk theft, and re-edits the Power Stock bestowal so All For One names Yoichi on the spot instead of the narrator doing it after his death.

Smaller changes include Kudo and Bruce researching in a bar rather than a nondescript building, All For One wearing his usual black suit against Bruce instead of a striped one, En's death censored with smoke in place of blood, the corpses of Kudo's family shown, and a montage of the people who carried him, Edgeshot and All Might among them, inserted when Dynamight admits he could not have done this alone. His birth scene relocates to that moment.