We are presented with the nightmarish image of Hogwarts as a black and brutal expanse presided over by
hovering Death Eaters and a cruelly imperious Severus Snape (Alan Rickman, in a brief performance of genuine depth).
so you're writting a review about a movie which YOU don't understand, the ghost - like characters are called DEMENTORS,
death eaters are just dark wizards, the «
hovering water dish» is called the pensieve, the truth about the elder wand is revealed way before, it was YOU that didn't know it, and I can go on but whatever, next time READ the book...