"A martial art?" Riku raised his brows. He could see it in the way Zuko moved, but... "A spell is a way of summoning magic. It looks like instead of using some weapon or words, you do that by moving your body a certain way." He narrowed his eyes in thought, wondering about how it was done.

"What I did was called Dark Firaga," he began, "and Firaga is a type of fire spell. But how you could 'bend' it?" Using the word like that felt bizarre. "You don't 'bend' or really use darkness like magic. You use it with this." He pointed to his chest with a rather grave expression.