Ghost in the Cowl - Ghost Exile, #1

Caina Amalas was a nightfighter of the Ghosts, the spies and assassins of the Emperor of Nighmar, and through her boldness and cunning saved the Empire and the world from sorcerous annihilation. But the victory cost her everything. Now she is exiled and alone in the city of Istarinmul, far from her home and friends. Yet a centuries-old darkness now stirs in Istarinmul, eager to devour the city and the world itself.
And Caina is the only one that stands in its way...