Many years ago, a primordial black mass was made. It was attacked by Odin, Vishnu, and Ra. A tuft of the black mass fell onto Earth and killed the dinosaurs. The black mass spreaded through Japan from early times to Feudal Japan. The Emperor wanted to get rid of the black mass with a poison arrow at the source of the mass. The arrow hit the mass and the mass gained a face, arms, a voice, body and consciousness. The mass became known as Aku. Aku ravaged Japan while the Emperor watched in horror.
—Christian Frates