Trevor Hoyle - Mirrorman [Kindle azw3]

With just nine days left to live, death-row inmate Frank Kersh is made a very strange offer by a powerful cult called the Messengers: in return for his salvation and the fulfilment of his every desire, he must thwart any threat to the cult's plans for world domination.

With nothing left to lose, Kersh agrees, and soon finds himself elevated to a god-like position, and with more power than he could ever have imagined. His success would appear inevitable, were it not for one man.

Cawdor. Unbeknown to him, his history is entangled with that of the Messengers, and over the generations he has unwittingly become their arch nemesis. To gain immortality, Kersh must destroy Cawdor, both in the past and present, but Cawdor proves a determined adversary. And he may just have found a way into Kersh's realm—that frozen moment between life and death in which Kersh now exists.

But time is ticking, and for Cawdor it may already be too late.