It looks like you’ve copied a detailed section from ScreenRant about the Marvel Cinematic Universe (MCU) series, Agatha All Along. The content touches on multiple theories, character revelations, and Easter eggs connected to the black heart mystery introduced in the show, with ties to WandaVision and the larger MCU.
The article reveals that the black heart from Agatha All Along episode 6, “Familiar By Thy Side,” doesn’t refer to Rio Vidal, as many fans speculated, but instead points to Billy Maximoff (Wiccan). It also delves into the connection between Agatha Harkness’ coven, and how Billy might have always been destined to be part of it.
There’s a discussion about Rio Vidal potentially being Lady Death rather than a Green Witch, and the show’s ties to Mephisto continue to fuel speculation about his MCU debut. The mystery surrounding the black heart in WandaVision also subtly hints at Billy Maximoff’s role, showing how these intricate details are woven across the MCU.