Satanism, as i understand it (I am not a satanist), is about chaos, hedonism, freedom and absolute liberty, this is opposed to the order and sanctity of something like Christianity. Order is by it's very nature an authoritarian concept as it removes Freedom in exchange for a kind of social order, you can ofcourse be free within a system, but only so long as the system allows it (Overt communism does not, the United States government does)
Satanism is an emphasis of liberty at all costs, an abandonment of what is good for a society as opposed to what the individual selfishly seeks. That doesn't mean that someone should be free to go off and murder a bunch of people, but that isn't really the focus of satanists so much as having sex with whoever they want or doing whatever drugs they want; this is in contrast to orderly societies that forbid such things despite the fact that they tend to be be "Victimless".
Any real satanist worth a crap wouldn't be a leftist because modern leftism wants to establish its own illiberal order. Not having the freedom to own guns or have free speech or to be protected against social and government persecution of the individual is in complete contrast to the goal of an actual satanist.
It is strange to say especially given the teaching of the bible, but Christians and Satanists at least have a fundamental understanding of each others goals and modern followers of each ideology have no real interest in directly interfering with their personal lives as readily as the left seems to want to (IE, a Satanists wouldn't rebel against a Christian's ability to have a nuclear family)
Once this is all over and the left is obliterated and no longer has so much control in government, entertainment, education and media, then perhaps we can have a discussion as to what individual freedoms the individual ought to have.
I think its a kooky religious version more diametrically opposed to Christianity.