Ariana Dumbledore
Just in case you missed it...
“’It destroyed her, what they did She was never right again. She wouldn’t use magic, but she couldn’t get rid of it.; it turned inward and drover her mad, it exploded out of her when she couldn’t control it, and at times she was strange and dangerous. But mostly she was sweet and scared and harmless” (Harry Potter and the Deathly Hallows pg 564--Aberforth describing what happened to his sister, Ariana Dumbledore).