Part 1: In a distant future there is an organization called Deava which had to fight against the so called "Shadow Angels", creatures that had survived for over

Part 2: 12,000 years whose only purpose was to destroy humanity. Apollo, a seemingly normal human, was in fact the reincarnation of a fallen Angel called Apollonius, who in turn had to fight against Touma, a Shadow Angel, along with his comrades in order to prevent the destruction of the Earth.