Changeling - AJ Pamerelle

Halmorians...an alien species reminiscent of the modern depictions of vampires, the last of these creatures that remembers their home planet has watched human civilizations come and go. They've watched the Halmorian's greed continue to tear them apart, and they have failed to make a difference. That is, until a human girl is changed into the youngest Purple-Eyed One.
Nikki Fairyn was an ordinary human girl, until she was kidnapped. Waking as a Halmorian, she found herself caught in an ancient war. Amidst prophecies, discovering her new powers, puberty, and figuring out who to trust, she'll have to be careful not to lose herself and everything she stands for.
As an unseen force guides her, perhaps Nikki is the vessel which can be used to save them all.