This was a thick book that I read over fifteen years ago that I never finished reading because someone borrowed it and didn't return it to the school library. I want to find its title.
The story takes place in a kingdom that is preparing for the a cycle of war, where every time the winds changes (50 or 100 years), invaders will try to cross the sea from another continent using airships with air balloons, filled with soldiers and warlocks. The kingdom has made several man-made island fortress along their coastline, filled with soldiers with war machines, sorcerers, and enchanters who act as the main guard/defence for the kingdom, calling lightning and fireballs, and using machines to stop and destroy and bring down as many of the invader airships as possible while countering the warlocks on board.
The book involved a man and a girl whose journey brought them apart in preparing for the imminent war.
The women found herself adept in magic and went to the academy in the capital to learn to be a sorceress.
The man found a different calling. With a good memory, he was sent to learn to become a mnemonic storyteller (to train with battle staff and fighting skill and mnēmonikos skill) who carried the history, literature of the entire culture in their heads. They used their knowledge to convey the kingdom's literature, poetry, history and stories to the people from generation to generation.
Both eventually "graduate". Sadly, and with great emotion, both have to part ways. She was sent to a fortress island and began her role as a sorcerer who will stand guard there. He, as a storyteller, began his own journey without her, going from town to town, village and soldier barrack, across the kingdom, telling stories of great men and their deeds, and courageous heroes who fought the war, to uplift the spirit of the people and bring valor to the soldiers stationed at the border and people in the coming war.
In brief, he meets a dragon (who used to be involved in the war in ages past), long thought to be extinct. He finds himself able to communicate with it and has a "born" friendship with it. The dragon teaches him to become a "dragon rider", a long-lost ability of his people (due to the "extinction" of dragons.)
The wind changes with the dread of war hanging on the kingdom. Airships start to blacken the sky again with soldiers and war machines battling each other.