Holly Lisle 
Vengeance Of Dragons [EPUB ebook] 

Kait Galwiegh is now a fugitive, seeking the Mirror of Souls in order to resurrect her lost family. But to get it she must battle with Crispin Abir, who believes the artefact will make him god. Both are terribly wrong; using the artefact will in fact unleash the souls of the long dead sorcerers who once before conquered the world. Held captive within the mirror, the magicians wait for freedom and the opportunity for vengeance.