The Kingdom of God is threatened by demon invaders. Satan assembles a third of the Divine Host in an attempt to overthrow God and His legions of angels, to place himself as ruler of the Celestial Kingdom. The angels that have formed an alliance with Satan are called Watchers, Grigoris, and Zones (known as Demonites). These angels have revolted against God by refusing to be servants to Adam. Diplomatic efforts have collapsed, and the region has plunged into anarchy. Chaos and turmoil have shaken the heavens and have weakened the suppression power of the seal. Now the Celestial Kingdom has come to encounter darkness.