Board Thread:Site Discussion/@comment-30940727-20170806154038

A lot is unknown about One For All, be it the precedessors or the reason why All For One gave his brother such a Quirk.

Let's be honest here, no matter how much they trained, the physical power of 9 people (Or 8, since Midoriya's physique is trivial compared to the others) can't possibly result in such a destructive force: Changing the weather with one punch? Wind pressure strong enough to blow a building away? Seriously?

So my theory is that the the so-called Quirk that "Stockpiles" physical power isn't what most people think it is, instead of passing a person's physical power on to his Successor (And that is after mutating with the 1st User's original quirk), the Quirk's ability is that the more the user trains, the stronger he gets, removing all limits whatsoever.

I mean seriously, we've all avoided thinking why the hell would All For One give his brother a Quirk that would allow him to - let's say - "Save" his physical power, as it is said that All For One didn't know about his brother's Quirk. So logically thinking, he gave him a way to get stronger, since - As the greatest villain of the time - he despised his miserable brother.

In conclusion, the Quirk that "Stockpiles" physical power actually removes all body limits and allows the user to continue getting stronger, combined with the 1st User's ability to pass on his own Quirk, they mutated and formed the One For All we currently know.

Midoriya for example, will have to train to a level where his body would be able to handle the full potential of One For All, and will then be allowed to increase the Quirk's base power.

Manga Spoiler

As we know, in his fight with Bakugou, Midoriya realized he could actually use 8% of One For All's power, I mean we already knew that he trained with All Might for 10 months at the beginning, and training a kid's body that much will already have it at its physical limit, as he probably can't get any stronger than that!

P.S: I always tried searching for a logical explanation to this, but since I never found any, I decided to make one myself for all of you who wanted to know. It might be incorrect, but I tried my best! 