Ghost in the Hunt. Ghost Exile, #3

CAINA AMALAS is the Ghost circlemaster of Istarinmul, the leader of the Emperor's spies in the city. With the aid of mysterious allies, she fights to stop the sinister plans of the ruthless Grand Master Callatas. But Callatas has spent two centuries preparing to remake humanity, and he will exterminate any who dare to oppose him. CLAUDIA ABERON DORIUS was once a sorceress of the Imperial Magisterium, yet now she is the wife of a high noble of the Empire.
Civil war rips the Empire, and the rebel sorcerers have targeted her beloved husband for death. Claudia has no choice but to work with Caina, the woman she despises most in the world, to save her husband's life. But a danger comes that neither Caina nor Claudia have foreseen... KALGRI is the Red Huntress, the centuries-old assassin of legend. She has killed kings and princes, sorcerers and alchemists, young and old and rich and poor, and laughed at their screams and rejoiced at the tears of their families.
She has slain countless innocents, and no one has ever stopped her. And her next target is Caina Amalas.