The Hexslinger Series

Set in the 1860s in an alternate version of our own West, the series introduces the concept of ordinary men or women who occasionally manifest as powerful magicians, called "hexes." These hexes are capable of great feats of magic individually, but have never been able to cooperate and use their powers in partnership. Each is self-taught,  using individual tricks and techniques. That is, until Reverend Asher Rook,, a former Confederate preacher who has lost his faith, survives his own hanging and manifests as one of the most powerful hexes ever seen. Considering himself damned, he forms a relationship with gunslinger Chess Pargeter, an openly gay man and close-to-psychopathic killer, then begins a career of banditry using the Bible to work black miracles and make himself unstoppable. His fearsome reign of terror draws Allan Pinkerton of the Pinkerton Detective Agency to send agent Ed Morrow on an undercover mission to infiltrate Rook's gang. And as Rook forms a dark alliance with an ancient goddess that threatens the entire world, Morrow must somehow convince Chess Pargeter to help.