No, I do not believe in a Satan, demons, god(s) goddesses etc. the idea of an "evil" supernatural being originated and evolved in much the same ways the "good" god(s) did, they were born out of ignorance and were/are fed by fear. later they were used as a political and societical tool for control and still is to a degree. I think Satan as simply symbolism for ego is a modern interpretation because it is harder for people today to believe in a literal "Satan" as a being and as it has since it's inception, religion is morphed to fit it's society. Satan is represented in the bible as a being just as real as Jesus, if we are to believe that the physical representation of satan in the bible is simply a symbolic one, then logically, the same would go for Jesus- what did he represent if only a symbol for something else?
There is a popular saying that "The greatest trick of Satan is convincing people he isn't real", considering all of the persecution,suffering, death, torture, wars, hatred, etc. that have been caused by the people that did/do believe in him, I don't think an "evil" being that revelled in the suffering of humans would want anyone to forget him. I think he would be very pleased that all the suffering was caused because of belief in him in the name of his nemesis "good god" by his "good" followers- I think he would want you to believe in him so that cycle could continue and he would laugh in hell (or wherever he is supposed to be).
Or we could just completely absolve all the perpetrators of these horrors through history that have been committed against millions of human-animal kind and hold none accountable for any of it except for a cosmic "bad guy", of course if it wasn't "Satan" or "God", it probably would have been something else, that is as long as people gave those beliefs as much power as they have the satan/god myths, and that is the trick. There are plenty of places and beliefs in this world where the idea of "satan" does not exist, or do some want to believe that Abrahamic/Judeo-Christian etc. beliefs and resulting off-shoot cultures are universal and binding to the entire world?