Curse: The Dark God Book 2 - The Dark God, #2

Argoth and Shim have only a short season before Mokad comes to annihilate them. If they're going to survive, they will need to raise an army of dreadmen and fell-maidens and train them in the lore. Argoth sends out a call to Groves throughout the western lands and begins to train Talen, Sugar, and three hundred others. But Mokad isn't waiting. Mokad has already sent an armada with armies from four glorydoms.
It has also sent its Guardian-a terrifying Divine everyone thinks is a sleth ally, coming with an invitation from Argoth himself to join Shim's men. Outnumbered and outmatched, humankind is about to lose its first chance in an age to fight against those who enslave them. Unless, of course, this new Grove can find a way to do what no other has ever done before.