The First Vampires (Children of Ossiria #0.5)

Jolana has served the Ossirian god of war as a seer for as long as she can remember. When he chooses her to be his instrument of destruction, she devotes herself to the task—starting with young Isa.

Isa is a healer and when Jolana comes into his shop, he knows she is trouble but the beautiful Eridae cannot be resisted. Soon, he is drawn into a war between gods that will alter the universe forever.