Book of Strikte

Although a family of blacksmiths, the Strikte family has an old prayer which is recited before battle. So as Theo one day finds himself having to fight a demon, he steps forward and prays:

“May the Gods of War bless my opponents as they raise their blades, for it will be the last time they do so. May the Gods of Peace comfort my opponents as they cry tears of blood while they lay dying in mud. May the Gods of The Harvest bless my opponent's family. For their children who raised their weapons against me will never return home.”

The rest of his actions is written here. In this book.