Sky Magic — B.V. Larson

In Sky Magic, the second book of the Haven Series, the Pact that has kept the peace for centuries between humanity and the Faerie is broken. Oberon, King of the Faerie, lost his Blue Jewel and can no longer command the marching Rainbow to keep the peace. Once again the darkest and most evil of his kind plague human lands. In defense of the Haven, a champion must be chosen to wield the Axe Ambros. A magical weapon powered by the legendary Amber Jewel, the eye of a long dead golden dragon, the Axe is difficult to master.

Written for a fast-paced read, Sky Magic is over 60,000 words long. (Which is significantly longer than Amber Magic).