I don't think Epicurean philosophy would say Harry Potter is satanic, ...however Harry Potter it is promoting "superstition" and that the material can be affected in a non-material way ...and so it is really the same as Christianity, just packaged differently.
Sure, but I can watch and enjoy Harry Potter and other fantasy media without genuinely believing in the supernatural. It’s fiction. I find the Christian argument against engaging with such media incredibly silly, and I would think it’s equally silly if Epicurean philosophy made the same argument - which for reference, I don’t think it does. I don’t have to believe in the existence of magic and trolls and dragons in order to enjoy watching Harry Potter, just as I don’t have to endorse violence to enjoy watching action movies.