The Song of the Sirin by Nicholas Kotar

An evil omen clouds the sky. A song of power returns. Can one man’s quest save the world?
Voran, a young warrior of Vasyllia, lives in a dying world. As blight ravages the countryside and darkness covers the sun, he can’t avoid hearing the rumors of an ancient spirit that devours souls. He feels powerless to fight the oncoming devastation until a mythical creature entrusts him with a long-forgotten song of power.
Armed with the song, Voran must hunt down the dark spirit before it becomes immortal. His quest takes him through doorways to other worlds and puts him on a collision course with seductive nymphs and riddling giants. With each step of the journey, the strength of the villainous spirit grows, as does Voran’s fear that the only way to save his world… is to let it be destroyed.
Inspired by the Russian fairy tale “Prince Ivan and the Grey Wolf.”