Windswept Desire. Gathering of Magic, #3

Camilla is the princess of the kingdom of Amoura, the daughter of a brutal human king who has harnessed the power of magical beings to conquer and extinguish his enemies. She is sheltered from the reality of her father's rule; carefree, light-hearted, until the castle is taken over by a dangerous being with the power of mind control who has plans to turn the whole kingdom against Camilla before turning it against the world.
Camilla's sworn protector, Aella, has been at her side since they were children. Irascible and commanding, even the stoic warrior cannot control herself when the desire that has been blossoming between she and her princess becomes all-consuming and impossible to ignore. But Aella has a secret that puts her at odds with her best friend, one that will push them apart despite their growing love. To save Amoura from utter destruction, she will have to reveal who she truly is, and risk losing her princess and the kingdom altogether.