There are different origins for all such beings and could each be said to be a lie, but there is one similar to that but ignores that these being also existed at the same time. GR dealt with Satan in the 70's after SS was dealing with Mephisto.
There is some throne that they are fighting over, the Hell Lords, that is called Satan's throne or some such which implies that he was real and is gone now, but it was not flushed out too much other than it was a fight to have it and unite all of the evil underworld places.
He may well exist, I am just saying it is complicated. Mostly because of shifting explanations and requirements of stories and the real world in the first place.
I mean at one point when the Hell Lords became more prominent and Satan was ruled out it was the same time that things like dungeons and dragons had to stop calling their devils and demons by those names and switch them to something that did not draw ire.
Really, the confusing nature of it is somewhat fitting for beings that are built on lies and twisted deals in the first place.
remember when they had Jesus show up to assist Blaze against Mephisto, but then back tracked that?