Havoc of Souls by S.J. Sanders

The world went silent when the mist came. Following a sonic blast heard around the world as the gates of Aites were thrown open, the mist clung to the mortal world, but it was not empty. Creatures dwelled within the mist, and when the mist left, they remained.
Yet, with the ravagers another came forth. The gatekeeper, Charu strode across the land in hunt of his quarry, those spirits which had broken through the barrier. With his lamp of souls, he moves over the world capturing the spirits and bringing death to those driven to madness, infected by exposure to their miasmatic taint. He will stop at nothing to accomplish his task.
The ravagers brought civilization to its knees, hiding out as an infestation within the city. Meredith was one of handfuls of people left in Ashton, barely clinging to survival as resources ran low. When a shift in power dynamics brings the people under the yoke of the ravagers, Meredith knows that her time may soon be up. She doesn’t anticipate being saved by a dangerous spirit bent on destruction.
Can love bloom and flourish between a grim spirit and a human woman with spirits running in havoc around them, and will their magic together be enough to save humanity from a crippling fate?