If there’s a theme in particular, I guess I missed it. But War in the Sun has a heaping helping of plot and character arc, so I can forgive certain other lacks. The sixth volume of the Preacher series opens with a look into the backstory of dickhead antagonist Starr, leader of the shadow organization that wants to use Jesse Custer as a figurehead to distract people while it achieves global domination. That out of the way, events quickly spiral out of control when Starr, Jesse and his companions, and the Saint of Killers meet in Monument Valley for an explosive confrontation that, unless I miss my guess, will have echoes throughout the rest of the series.
At the very least, all of the major characters have reached the nadir of their respective emotional arcs. (Even Arseface, who is inexplicably still present in the story. And, well, not including the Saint of Killers: I expect his happened rather longer ago. Anyway, he’s more a force of nature than a character.) All that remains is to see how and if they can recover as the storyline starts moving into climax mode. I, for one, can hardly wait.