The end of the Prelminaries

Nero took out his spell guns whispered something to them and filled them with his mana. When he heard Julia announce the start of the battle, he saw several of Xia's chakrams coming towards him. Nero used the spell guns for a precision wind spell to hit the chakrams coming his way. 

The spell guns were weapons that has stored spells within them, and all you need to do to activate those spells was to first insert mana into them, then press a specific button on the handle, and finally pull the trigger to fire out the spell. Of course, once all the spells that were stored have been used up, you can also simply insert mana into them and it will shoot out balls of pure mana. Even though Shooting out the balls of pure mana was stronger it also drains one's mana supply faster.