The Christian concept of Hell "borrows" from other religions when its not basically INVENTING the idea as Christianity went along.
After all, the Bible doesn't state there was a 'war in Heaven' & Satan was thrown to Hell. That's a traditional story that was tossed around in Christian 'fan fiction' but never part of the official canon.
John Milton was the one who gave Satan his famous line about "it is better to rule in Hell than serve in Heaven". Last I checked, Milton's work hadn't been added to The Bible.
Interestingly, if you read the Apocrypha (the early Christian texts that the early Church didn't select for The Bible) you'll find an episode where Christ goes to Hell. Parts of that story are heavily influenced by a story about the Buddha, where one of his followers asked him where would He go after death. To which the Buddha goes "To Hell". When asked why, he replies "Where else is consolation needed more?"
Anyway, if demons, etc. are torturing people in Hell, who's torturing mankind by denying him liberty & safety in THIS world?
Oh yeah, his fellow man - a greater evil than any demon. Heck, look at the history of mankind.
Satan didn't need to do anything to cause mankind to do some pretty sick things to itself.
'bout time mankind takes responsiblity for the evils of the world instead of blaming a guy in red PJs & a goatee.