Merlin's Moon, by Annabelle Jay
Half-human, half-dragon Mani hatched from an egg and was adopted by Allanah, a human woman who discovered him after the death of his dragon mother. He possesses abilities he’s only beginning to understand, and every night he takes the form of a blue dragon.
When Mani’s secret is revealed, he takes refuge at the wizard Mansion. There, he encounters the Animal Guard, a group of people who share his affliction. But the members of the Animal Guard are under a curse by the sorceresses, and they need Mani’s aid to break the spell and resume their human forms. Growing romantic feelings for the wolf-boy Lup convince Mani to offer his help, but Mani’s own developing powers might destroy any chance at a relationship. The world of magic is changing, and as Mani and his friends fight to stop the evil sorceresses from using the deadly North Star, they must figure out what places they will hold when the battle is over.