Daimonion

Dati Amon wants to be free from his satyr master and he hates his job-hunting human children who display demon balefire. Every hunt has been successful, except one. A thwarted attempt ended up as a promise to spare the child of a white witch, an indiscretion Dati hopes Master never discovers.
But Master has devilish machinations of his own. He needs human-demon hybrids, the Daimonion, to raise the Dark Lord to the earthly realm. If Master succeeds, he will be immortal and far more powerful.
The child who was spared is now a man, and for the first time in three hundred years, Dati has a reason to escape Master's chains. To do that, Dati makes some unlikely alliances with an untrained soulless witch, a self-destructive shape shifter, and a deceitful clairvoyant. However, deals with demons rarely go as planned, and the cost is always higher than the original bargain.