Maria
"You understand. As a demonstration, I will attack you. Avoid taking any damage from the attack."

*The man holds his sharp shield back for a wind-up of two seconds, then rushes forward in a **Sliding Dash.***
Tim
Likewise, as the man charges up, the smaller figure holds his arm out- enveloping his hand in a flurry of blue sparks, summoning a dark blue keyblade, ``Moon Below``.

He quickly holds his other arm out, placing his free hand against the flat side of the blade to have the wide part face outwards- using all of his might to ``Block`` the attack. It's a heavy strike on impact, from what he can feel.
Maria
"An acceptable guard. Did you feel pain?"
Tim
Silence for a few moments, as he drops his arms to his sides and allows the keyblade to dissipate into the sparks it came from.

"My arms feel heavy.. Strain, i think. Not quite sharp, yet... A dull feeling."

Considering he blocked a strike from a giant, it's normal to be feeling this way after taking a hit head on with a guard. Especially considering the difference in physique.
Maria
"That strain is from your own exertion. As your strain builds, you will be less able to fight. Your goal must be to minimize it."

"I will attack you again. This time, exert yourself less in your guard. Rather than strain yourself avoiding pain, absorb it."

*The man winds up again, this time leaving a trail of light as he performs **Zantetsuken.***