An Ember in the Ashes Tome 4 (Broché)

The long-imprisoned jinn are on the attack, but for the Nightbringer, vengeance on his human foes is just the beginning. At his side, Keris Veturia declares herself Empress, and calls for the heads of any and all who defy her rule. Laia of Serra, now allied with the Blood Shrike, is determined to stop the approaching apocalypse. Throwing herself into the destruction of the Nightbringer, she awakens an ancient power that could lead her to victory - or to an unimaginable doom.
And deep in the Waiting Place, the Soul Catcher seeks only to forget the life - and love - he left behind. But to uphold his oath and protect the human world, he must take on a mission that could save - or destroy - all that he knows.