The winner

Fwuummm!!

   Susan swiftly swung her sword towards Nathan, unleashing a powerful slash which moved through the air at tremendous speed.

   As she released her attack, Nathan also launched his, sending out a long yellow slash.

Swoosh!!

    Bright yellow flame burned ferociously around the slash, eager to devour all that stood in its path.

BWOOSH!!

   Within an instant, the two attacks collided in the air, the force behind their collision sending out a small shockwave of mana, which swept across the stage.

   The light from Susan's slash wave shone brightly, slowly pushing back against Nathan's slash.

   Nonetheless, Nathan's attack didn't give up easily. 

  Its flame burned even brighter, slowly eating into Susan's spell, reducing it bit by bit.

   Meanwhile, Nathan and Susan simply watched as their attacks fought violently in the air, the both of them too exhausted to even lift a finger.