Rapture: Book Three of the Bel Dame Apocrypha

After years in exile, Nyxnissa so Dasheem is back in action in service to the bel dames, a sisterhood of elite government assassins tasked with eliminating deserters and traitors. The end of a centuries-long holy war between her country, Nasheen, and neighboring Chenja has flooded the streets of Nasheen with unemployed - and unemployable - soldiers whose frustrations have brought the nation to the brink of civil war. 
Not everyone likes this tenuous and unpredictable "peace," however, and somebody has kidnapped a key politician whose death could trigger a bloody government takeover. With aliens in the sky and revolution on the ground, Nyx assembles a team of mad magicians, torturers,and mutant shape-shifters for an epic journey across a flesh-eating desert in search of a man she's not actually supposed to kill. 
Trouble is, killing is the only thing Nyx is good at. And she already left this man to die...