Ruins of Magic by Julie Trettel

Dark magic has come to Gavalon and the once thriving kingdom is falling into turmoil.

Arion continues to train under Zallon, the High Keeper of Magic, but a quest issued by the King has him partnering up with Valaria once again in search of his own answers. Arion’s growing feelings for the princess could hinder their journey.
Valaria has never felt like she has lived up to her father’s expectations of a princess and future ruler of Gavalon. She strives to prove herself to him when she joins Arion on his quest. But she may be in over her head working so closely with the man that has continued to star in her deepest fantasies.
The unlikely couple will face trials and tribulations around every corner as their path weaves throughout the kingdom to lost ruins rich with untapped magic and secrets that may give light on Arion’s past. New friends will help them along the way, but enemies lurk around every corner.
Will the magic found in the ruins help them battle against the darkness or will it prove to only strengthen their unknown enemy?