He Is the God of the Apocalypse

In a zombie-ravaged world, Zoe and Hazel seek the Golden Lion Citadel. Zoe marries drifter Leo, then betrays him for a spot, having an affair with permit-holder Jasper and humiliating Leo--unaware he's the Citadel lord. Cast out, Leo discovers his true savior is Serena, lord of Hope Haven, who's been searching for him.