All-Might Had Another Quirk - My Hero Academia Theory

Those up-to-date with My Hero Academia know that Toshinori Yagi, a.k.a All-Might, finally lost his quirk One for All after his last fight with All for One. Many probably assumed that his muscled form would be gone for good, but that wasn't the case. All-Might can still revert to his muscled form for short periods, but how is this possible? How can a man have two different body types? It's almost like he still has a quirk.

Fans who noticed this started looking back at previous episodes and discovered something. Gran Torino mentioned that when All-Might first got One for All, he could control its power easily. He even notes that Toshinori never had any problems handling the power of One for All. This could be because Toshinori's version didn't have as much power, but even with that, All-Might was the strongest hero during his time.

Unlike Deku, a young Toshinori could handle the greatest power of his time in his young body. It doesn't make much sense unless he already had a quirk he was unaware of, that didn't come into play until later on. Could this mean Toshinori's ability to handle One for All's power has to do with a hidden quirk? Theoretically, yes, but at the beginning of the manga, it is mentioned that Toshinori's 'true form' is his muscle form and that his skinny form is due to the injuries. Even with that explanation, it's still odd that he has two different forms.