Stygiophilia is a fetish that describes sexual arousal at the thought of going to hell. The term comes from a combination of the word stygian, an adjective describing anything pertaining to the river Styx, a river in the underworld in Greek mythology, and philia, meaning love.
There is very little information about this fetish or whether it actually exists anywhere beyond the internet. It is defined in "Forensic and Medico-legal Aspects of Sexual Crimes and Unusual Sexual Practices," a book by Anil Aggrawal published in 2008, but there appears to be no porn centered around this topic, and no online fetish communities of people with this fetish.