Dementors, Death Eaters and Voldemort himself will apparently make an appearance, as will mountain trolls, Thestrals, and Aragog the spider.
However, while previous projection shows have been more about bright lights and spectacle, Dark Arts at Hogwarts Castle is being promoted as being more intense and featuring the darker side of the Harry Potter universe.
The new show will be a projection experience similar to ones that have been done at the parks before, like The Magic of Christmas at Hogwarts Castle which gets brought out at the holidays.