Sanderson, Brandon. Stormlight archive #5

"Dalinar Kholin challenged the evil god Odium to a contest of champions with the future of Roshar on the line. The Knights Radiant have only ten days to prepare--and the sudden ascension of the crafty and ruthless Taravangian to take Odium's place has thrown everythinginto disarray. Desperate fighting continues simultaneously worldwide--Adolin in Azir, Sigzil and Venli at the Shattered Plains, and Jasnah in Thaylenah. The former assassin Szeth must cleanse his homeland of Shinovar from the dark influence of the Unmade. He is accompanied by Kaladin, who faces a new battle helping Szeth fight his own demons--and who must do the same for the insane Herald of the Almighty, Ishar"--