Thread:ChocolatEyes613/@comment-5679696-20161201194210/@comment-6175354-20161201212729

Well, everyone figured out that Ariana was an Obscurial. How else would Grindelwald know they still existed? Other than the fact that he appears to be a Seer, of sorts. It is also pretty obvious that Aberforth was so upset, because Albus and Gellert planned on exploiting Ariana's powers, in order to ignite a war. Remember, they planned on taking her with them, while they gathered followers.