Agatha All Along's double-billed finale not only confirmed that the Witches' Road was magically manifested by Billy, it revealed that Agatha has been using the idea of it to trick witches and absorb their powers for centuries. With that, Marvel fans have set about explaining how it recontextualizes WandaVision's conclusion, and how "stupidly powerful" Wanda must've been to have bested Agatha back in Westview...
"On top of being the Scarlet Witch, she also absorbed a hundred-years worth of magic from other dead witches that Agatha sucked the life out of. I mean, Agatha's kill count had to be in the thousands," a viewer suggested on Reddit recently. "It's a bummer Agatha All Along didn't come out before [Doctor Strange in the] Multiverse of Madness and given context to Wanda taking Agatha's power, because they could've shown a cool horror element of the souls of the witches Agatha betrayed talking to/haunting Wanda."
