Caine's Law - Book 4 of the Acts of Caine

Some laws you break. And some break you. And then there's Caine's Law. The assassin Caine: a civilized man who embraced savagery, an actor whose life was a lie, a force of destruction so potent that even gods thought twice about crossing him. Now the legendary killer is back for his most stunning and bloodthirsty performance yet. Caine is washed up and hung out to dry, a crippled husk kept isolated and restrained by the studio that exploited him.
Now they have dragged him back for one last deal. But Caine has other plans. Those plans take him back to Overworld, the alternate reality where gods are real and magic is the ultimate weapon. There, in a violent odyssey, Caine will face the demons of his past, find true love, and just possibly destroy the universe. Welcome to the world of Caine: Assassin. Hero. Superstar .