Michael, the holy angel in heaven, the shadow of the Lord God, possesses the beauty and power that even God cannot resist. For the sake of his beloved Lucifer, he broke with God and chose to fall to heaven, becoming the fallen God of Destruction - Blood Moon King. When Lucifer blocked God's attack for Michael in the Holy War, the Lord God sealed Michael in Paradise Lost at the cost of his own body.
Lucifer was originally the Archangel of Heaven and the twin angel of Michael. He later fell from heaven and became the Demon King and founded the Demon Realm. During the Holy War, he blocked the attack of the Lord God for Michael, and his body collapsed and entered reincarnation.