This is Braveheart's Rank. 3 form, when he is at his most strongest.
To put it into perspective, if Rank. 2 learning to control his power and use it efficiently, Rank. 3 is where his strength skyrockets.

First of all that his armor, is now indistinguishable from his actual body and makes him impervious to physical attacks, swords and bullets either bounce off him or shatter on contact. And his basic attacks are boosted due to his energy flowing through his muscles, expanding them to increase his strength.

He has also learned more on the manipulation of air as well, now capable of sucking air into a sphere called an Air Bullet that he can shoot out at high speed. He can also manipulate the air to shoot out from the center of his Wing Ring to propel him to at least three times his normal speed. But can be forced even faster.
He now forms swords on his Wing Ring akin to feathers, these Feather Blades can be separated from the Wing Ring to preform a furry of attacks.

There is a downside, ironically it's that his power is TOO powerful, even for him. The energy in his muscles strains the fibers to the point of tearing. And while he is immune to most physical damage, blunt force trauma is a major issue to him. In fact, during one of the first times he used this form, he punch something so hard that it broke his own arm
(Although what he punched was completely obliterated) and it would take an entire year for it to heal without magic.

All this and it's only part 1, well, hope you enjoy.