“Good,” Harry said, genuinely. He let the fire die too, but didn’t pause to let him reassess or change anything about his thinking. Immediately he called out ‘Forzare’ and sent out a rushing thrust of physical force that collided with his circle and drew up like a shield against shield in battle. It pushed back by nature of the momentum, but Harry held. Not with his full might by any means, he wasn’t trying to hurt him, but he wanted to test him fairly too and let him get an understanding of the force resisting drew upon. Will, yes. And strength. Magically and bodily. At least, for Harry it was a bodily feeling. He could be worn down by maintaining a shield that was beat upon by something bigger and stronger than him. He had countless experiences that said exactly that.
And while he’d grown stronger and developed better endurance he was still only human. He pushed against Kvothe’s circle, but refused to ram his magic down his throat more than that. He let up shortly after and nodded his approval.
“You lose concentration on the circle you die,” he said simply, “My solution has always been to hold it, catch your breath, decide the next move then go from there. But if you play with it before you have to run off and save the world then you can add elements that become familiar in your set up. But I wouldn’t weaken my shield in front of someone who is stronger than me or experiment in the middle of a fight.”