I Learn to Kill Gods in an Asylum

Have you ever thought that behind the city filled with neon lights, monsters from ancient tales reside? Have you ever thought that high above the sky, behind the moon, stood a god watching over the mortal world? Have you ever thought that in this crowded 21st-century city, there are superhumans who are Seraph's agents? In this society ruled by humans, multiple weirdness lurk within. Michael the Seraph, Hades the Ruler of Hell, Poseidon the god of the sea where have the gods of Xia gone? In this world that belongs to "man", "Mythical beings" must be eliminated.