There isn't really much about eternal torture or damnation back when Satan was still an agent of God, and he certainly wasn't in charge of Hell. All the talk of gnashing teeth and lakes of fire was originally metaphor for how much it sucked, not literal.

Hell isn't a place, it's a state of complete lack of Grace. The idea is that everyone has a 2 way connection to God, and all good feelings and emotions must come from it. People are free to reject that connection by committing mortal sin, but "the line stays open," as long as someone lives. Honest repentance is accepting the connection back. If one dies before accepting grace again, God shrugs and accepts they aren't interested, and cuts his side of the line. This leaves an existence with zero positive thoughts or feelings, best case scenario is eternal meh. Of course, it was hyped up to be awful to help convert and maintain control. And, ofcourse, Satan did do a bit of torture here and there, but it was generally all on living folk to test them.