The Black Company

The Sinkers breathe poison so no one else has to. Branded monsters by the Empire that created them, Corin and his company of outcast soldiers hold the Iron Pass by inhaling the toxic Miasma that turns ordinary men to ash, carrying the names of their dead brothers tattooed in cremated ink on their skin. Abandoned by the Silver Legion, starved into rationing graves before food, and betrayed by the very command structure that made them, the Black Company breaks its blood-oath and chooses freedom instead - allying with an ancient golden weapon buried beneath their fortress and daring an Empire two hundred years in the making to come and take it back.
But something older than the Empire, older than the Sinkers, older than the war itself, is stirring in the dark beneath the Iron Pass, and it has been listening the whole time. A grimdark war fantasy about the soldiers an empire threw away, and what they build from the wreckage.