The Raven Perches at Dawn

The power of the blood pact is "the equivalent exchange of souls." Awakening the Blood Ancestor requires an immense amount of soul energy, not from ordinary souls, but from the soul link forged by a blood pact between a vampire prince and a human demon hunter. The prince provides the essence of darkness, while the demon hunter provides the faith of light. The energy produced when the two collide through the blood pact is enough to tear open the final crack in the Blood Ancestor's seal.