It seems that All For One knows more than it seems…
The new ability “Simple Growth” of Tomura Shigaraki, the current heir to the All For One, could have been a consequence of the investigations of his team led by doctor Kyudai Garaki. This article will contain a couple of spoilers for Kohei Horikoshi’s work. If you don’t want to be taken away by the surprise of following this work on your own, you can read it through the streaming service of MangaPlus by Shueisha.
The second batch of Nomu from All For One were not as strong as their predecessors, but showed slightly improved brain power. At least enough to handle multiple tricky Quirks like smooth energy absorption and release, strength enhancement, and control over a prehensile tongue. This batch of Nomu was eliminated even faster than the USJ, but the new abilities they showed showed that All For One was still working hard behind the scenes for a more important ultimate purpose.
The Nomu that fought in Fukuoka was the biggest indicator of how close All For One came to achieving their ultimate goal. He had as much strength as the one All Might defeated in the USJ, but displayed a level of sensitivity that had been lacking in all the Nomu before him. He spoke with a clear objective, to fight against the strongest, and as he did so, he learned and adapted to Endeavor’s tactics with alarming speed. This was the first Nomu that seemed to be tolerating multiple Quirks while retaining a bit of his identity.
This Nomu also exhibited the first hints of an ability similar to Shigaraki’s super powerful “Simple Growth” with which he terrifies pro heroes in current MHA chapters. To prevent the reinforcements from interrupting his battle with Endeavor, the High-end Nomu expelled several other fully grown Nomu from inside it. They were of the white variety, thus much less powerful, but still considerable masses that High-End had created from within with no reduction in their own size. It was Simple Growth in its early stages, except that the new “growth” did not remain attached to the host body.
After All For One was imprisoned, his friend and colleague Dr. Garaki continued his experiments on Nomu. Their efforts produced their mutual crown jewel in Tomura Shigaraki.. All of his knowledge of quirk transfer and ego retention poured into the process that gave Shigaraki the power he now has, and which All For One is actively usurping.
Tomura Shigaraki, his power came from experimenting with Nomu in My Hero Academia
If he manages to completely overwrite Shigaraki’s consciousness with his own, All For One will finally have won the one prize he’s been chasing for decades: a perfect All For One Quirk within a body literally built to handle the number of evolutions his continual consumption of foreign Quirks. It’s been explained recently, but a closer look at Nomu’s progression throughout My Hero Academia shows that All For One never tried to keep their final project a secret.
As My Hero Academia’s long-running story slowly winds down, many of the final arc’s big reveals end up providing context for previously innocuous details and revealing clues they never intended to hide. Shigaraki Tomura seems to have finally mastered simple growth, much to All For One’s delight. After all, it has finally become the perfect vessel to utilize the full potential of All For One. The concept of Simple Growth may have only been explained recently, but a closer look at Nomu’s progression in the series showed that All For One never tried to keep their latest project a secret.
Since the beginning of MHA, the Nomu have made a name for themselves as Harbingers of the League of Villains. There was never a League raid that didn’t involve Nomu and during the League’s first attack on the USJ, one came eerily close to defeating All Might with the help of Shigaraki. That first Nomu was able to simulate strength comparable to All Might’s without the aid of a Quirk.. However, despite all the strength of him, he was nothing more than a mindless puppet, bound to fulfill Shigaraki’s word and unable to take the initiative himself, it was until the latest experiments that this was possible.