Chrysalis - D. M. Youngblood - Bog

BOOK TWO IN THE KEEPER OF THE SPHERE SERIES She has the power to heal, and the power to destroy ... Dee Connor, the latest Keeper of the Sphere, is tasked with removing the enemies of Earth and preventing its destruction. To do this, she enlists the help of the Tuatha de Danann, a race of supernatural beings who were banished from Ireland centuries ago. The fate of the Earth will hinge not on Dee's mastery of magick or expertise in battle, but whether she can survive the transformation necessary to succeed - without destroying herself in the process.