When she can breathe again, an explanation of Begonia Butcher’s Theory of Conversant Magics comes out slowly, full of tangents of her personal experience that Harry will believe. He mightn’t agree with a theory but he’d never call her a liar. Finally, she says, "I’ve felt Marvolo’s magic before and yours, Harry, it’s just as strong. Stronger, maybe, given that when your wands met you pushed his spell back to him."