Hidden Power of Magic Arts

A clear, melodious peal split the air when Korra's fist collided with the Aegis. The note penetrated every sparring battle and training session with ease, drawing the attention of soldiers, onlookers, and camp followers alike. Even the sixth-level mages paused their spells and glanced over, attention set on the unusual noise.

When the haze of water and fog generated by her attack cleared, Korra stepped back with awe on her face. A single hairline crack ran through the Aegis, but even as we watched, it rapidly knit together, drawing only a fraction of mana from my soul for the repairs. 

Murmured whispers rose and fell like waves, sweeping through the training grounds as soldiers inquired as to the source and those nearby explained it to them. Korra approached the ball again and tapped it lightly with her finger, making sure it was actually still there and not some illusion.

"Just what did you do to that spell?" she asked, gaping at me.