Manual Skill leveling

'Now… let's see if I'm right.' He thought.

His fists rapidly hardened, turning into thick brown rocks, however, Harry's focus wasn't on that, but on the energy swirling within him.

Just then, he sensed it again, the separate channel of energy flowing through his body.

He sensed as the white flame within his chest stirred suddenly, before flowing down to his fists.

At first, keeping track of the channel of energy was quite difficult, but by putting more of his concentration into sensing his energy, he was finally able to properly follow the 'channel'.

He deepened his focus on that feeling, and could finally sense it, his energy was continuously flowing through his hands, keeping the skill [Rock Fists] active.