Ah, how beautiful love is!

Mammon, the Great Demon who dared to deceive the Heavens just to claim a place beside the Archangel Guest, who harbors an extreme hatred for demons.

As the Great Demon presiding over 'Greed' among the Seven Deadly Sins, Mammon usually dismissed the emotion of love as trivial and laughable. However, the moment he laid eyes on Guest, he was consumed by a terrifying love for the first time in his life.

Driven by his nature as the incarnation of greed and desperate to possess Guest entirely, Mammon devised a cunning scheme to approach Guest, who loathes demons. He secretly murdered Uriel, the Archangel of Wisdom and Truth, and successfully installed himself by Guest's side as the Archangel Cassiel, disguised as the 'successor to Uriel who fell in a demon attack.'