The Poison of Fate. The Fates, #1

Three siblings; one on the verge of death, another scheming to right a wrong of the past, and the third, resisting the call to power. But the gods will not take no for an answer. Now they wish to make a wager, who, if any, can acquire a soul from the Neliss Clan's heirs the fastest. But these three siblings have a plan of their own, and no good will come from interfering with siblings born from a prophecy.