All Might's muscular form was a unique result of handling him One For All and his injury. Deku cannot access a muscular form like All Might despite having the same Quirk. Deku's access to the vestiges ...

The Quirk One For All and how it works is one of the biggest mysteries throughout My Hero Academia. Deku has to train his body relentlessly to be able to hold the Quirk, and even then, his limbs break ...