Pauldron

You spring into action, though to her eyes you're barely conceivable as a blur.

You cross the distance at the speed of light to stand beside her. She's still looking in the direction where you were sitting, as you continue to move at unimaginable speed, and your perception of time is sped up at the same time, allowing you to savour every moment and take your time, as it were.

Your nimble fingers set to work, reaching near her armpit in order to loosen the straps holding her right pauldron in place. You then take it off, exposing the gambeson shirt underneath. You are about to walk back, when you realize you might as well take both.

You walk back to the bench you were sitting on, and stack the pauldrons on the market table next to you. Then you allow yourself to slip back into the normal speed of time.

The knight was about to speak, probably to bellow some clichéd response to you accepting the duel. But the words appeared stuck in her throat when she noticed her pauldrons, stacked next to you on the table. She glanced at her own shoulders, confirming they were indeed gone. Her face spoke volumes of confusion.