Offence is the best defence!

   A surge of mana rose up behind Trent's, and his eyes widened in shock.

  "Shattering Rocks!" Wes shouted, with a smug smirk on his face

Whoosh!

    Four medium sized rocks appeared behind Trent, before shooting towards him at rapid speed.

   As the rocks closed in on him, they swiftly broke up into numerous small stones, each one flying forwards at even faster speed. 

   "You think such a weak spell would affect me? Pathetic." Trent muttered, swiftly conjuring a small barrier of water behind him. "Water barrier."

Slosh!

   The stones crashed into the barrier, instantly crumbling into tiny brown particles.

   Since they were only casted with the left over mana from the last spell, they were easily overpowered by the water barrier.

   "Heh. As expected, you blocked it easily." Wes mumbled, with a wry smile on his face.