"Hogwarts last year... it was horrible beyond comprehension. I had to. The Carrows didn't teach Defense Against the Dark Arts but actually embraced and employed Dark Spells. They didn't care to teach us how to handle the aftereffects of it, only how to use it. With great reluctance, I learned how to safely wield it under Dumbledore. One of the reasons why they were so few fights and injuries was because I controlled some of the most volatile Slytherins that year under the Imperius Curse."