Next I looked at Hades, The god of the underworld, and places he is linked to. I particularly like the image from Disney's Hercules of Hades' boat on a river full of souls
I liked the idea of using an unconventional use of subterranean and underground, so started to look at underground bars. I like the idea of a secret cult or society, or a secret meeting taking place somewhere.
I then decided to look at unconventional perceptions of God, and liked the idea of using a manipulative and charismatic character, someone that people wrongfully look up to as a god. I did some researches into charismatic villains such as Charles Manson who relevantly claims he "rules the underworld"