"The entire Wizarding World knows that Al excels at Transfiguration, but few know just how far he has taken it.
I can tell you plainly, Will: Al has already touched the limits of what a wizard can achieve. Of all the countless wizards throughout history, Al stands at the pinnacle of Transfiguration."
"The pinnacle of Transfiguration?" Will looked thoughtful. "So, reaching the top allows you to receive magic's response?"
Grindelwald nodded. "That is Al's method: learning, researching, grasping the truth, surpassing everything, and making magic take notice of him and favor him.
That is the response of magic."
Will's thoughts were a little muddled-no wonder Dumbledore had always been certain he would receive magic's response.
Will looked at Grindelwald. "Then the other path..."
This time, Grindelwald spoke quite casually. "When magic takes notice of a wizard and favors him, that is the response of magic.
Magic is the power of the mind. So, what if an immense power of the mind were used to influence magic?"
"Using the power of the mind to influence magic, and the mind to anchor yourself?"
"Exactly." Grindelwald nodded. "That is why you need enough 'believers.'
Everyone's mind can anchor their own self. If something goes wrong with a wizard's memories and they no longer believe they are a wizard, they will be unable to cast magic.
If a wizard resents and represses themselves, they will become an Obscurial.
But to retain your sense of self within the 'response of magic,' you need enough minds to anchor it."
Something suddenly occurred to Will, and he frowned, sinking into thought.
Seeing Will fall silent in thought, Grindelwald actually breathed a sigh of relief-Will was still a child, after all, and there were many things he did not yet clearly understand.
Will, however, was thinking about his