Le gros méchant c'est toujours le Dieu chrétien et non Satan. 
https://the-sinking-city.fandom.com/wiki/Kay

https://the-sinking-city.fandom.com/wiki/Kay
It would seem that Kay is a euphemism for the Judaeo-Christian God. It is likely that this is due to the fact that the developers probably felt that forcing players to live in a world where this was overtly stated may have put players off.