Devil's work (The Twilight Hunter)

Shawn Crowley is riding back from his latest adventure when he comes across a small farm. Simply looking for a place to water his horse he stops in. What he finds is an elderly man on his death bed. His last request is that after he's buried he wants the house burned. Shawn takes his body to a nearby graveyard for burial. In the middle of covering the grave Shawn is attacked. A group of grave robbers attack and knock Shawn out. While he is knocked out they break into a crypt home to a powerful demon. When Shawn wakes he finds the demon sitting next to him He promises to help Shawn return them to the pit in exchange for his help. The Demon is named Alferious. And he is what is known as a dire smith.
He makes weapons in Hell and sometimes for humans. As it happens he has a problem that Shawn can help with. Someone slipped into the pit and stole his favorite hammer. And not just any hammer. A hammer that is powered by human souls. It's part of the pit and not meant for the world of men. It's a thing that corrupts any people around it and is a beacon for demons. Alferious reveals he was in the crypt sealing up a door to the pit. And he needs his hammer to finish the job.
Shawn has to track it down while Alferious keeps the demons from pouring out of Hell.