Film Theory: Dumbledore Was Secretly Weaponising Harry Potter

4. The Importance Of Dumbledore’s Family

Dumbledore’s family history is also very important to establish his thinking around Harry Potter. As one compelling theory suggested in the wake of the release of Fantastic Beasts, Dumbledore grew up with an Obscurial in his own family. His sister Ariana had been attacked by Muggle boys as a child, which prompted her father to lose control and attack her abusers, leading to his arrest and imprisonment in Azkaban while she was hidden by her mother.

That trauma is a text-book Obscurial origin story and the way Ariana was described by Aberforth as he related her tragic story and his own estrangement from his brother fits that theory too:

“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 drove 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.”

Compare that to how an Obscurial is described in Fantastic Beasts:

"Before wizards went underground, when we were still being hunted by muggles, young wizards and witches sometimes tried to suppress their magic to avoid persecution. So instead of learning to harness or to control their powers, they developed what was called an Obscurus.”

And, more importantly, how JK Rowling herself described Obscurials:

"An Obscurus is developed under very specific conditions: trauma associated with the use of magic, internalised hatred of one’s own magic and a conscious attempt to suppress it.”

It all fits. If Ariana wasn't an Obscurial, everyone around her - particularly her brother who would come to have specific experience of them later - would have had cause to believe she was one if they knew what they were looking for. The fact that there could be two magical "illnesses" that presented themselves so similarly is a little unlikely.

Because, on top of his sister, who may or may not have been an Obscurial, we know of one concrete case of an Obscurus that Dumbledore WAS aware of, thanks to the timeline of the Fantastic Beasts movies. The case of Credence Barebone.