Shout-Out: When the Heavens Fall by Marc Turner

If you pick a fight with Shroud, Lord of the Dead, you had better ensure your victory, else death will mark only the beginning of your suffering.

A book giving its wielder power over the dead has been stolen from a fellowship of mages that has kept the powerful relic dormant for centuries. The thief, a crafty, power-hungry necromancer, intends to use the Book of Lost Souls to resurrect an ancient race and challenge Shroud for dominion of the underworld. Shroud counters by sending his most formidable servants to seize the artifact at all cost.

However, the god is not the only one interested in the Book, and a host of other forces converge, drawn by the powerful magic that has been unleashed. Among them is a reluctant Guardian who is commissioned by the Emperor to find the stolen Book, a troubled prince who battles enemies both personal and political, and a young girl of great power, whose past uniquely prepares her for an encounter with Shroud. The greatest threat to each of their quests lies not in the horror of an undead army but in the risk of betrayal from those closest to them. Each of their decisions comes at a personal cost and will not only affect them, but also determine the fate of their entire empire.