Exquisite Blood: The Heretic Onmyoji

In an era when only a thin boundary exists between mortal and supernatural realms, demons steal ten powerful artifacts known as the Sacred Treasures from the human imperial capital. The emperor issues a decree to the onmyoji who serve and defend the empire: recover the Treasures at all costs. Among their number is the brilliant renegade, Fuzuki, who sets off in search of the first Treasure.

(Source: Manga UP! Global)

Alt. Official English: Square Enix (vol.)