The Titan's Bow

Jack wants to become a warrior. He and his friend Zack have been waiting to train forever, but the waiting list was a mile long to get a master, and seeing that Jack has very few physical attributes, other than basic archery, it was also very unlikely that he would get a spot. He also has basic Spell casting, but only can use the simplest of spells. Meanwhile, The ancient titans seem to be rising again, and entire castles are going missing!!! What will Jack do if he isn't accepted? Who will stop the titans? And where in the world is that Castle? One wisend old wizard suspects that they're all related, and he may just be right...