WandaVision’s seventh episode revealed the witch Agatha Harkness as Westview’s big villain, but Mephisto may still be hiding behind her plans. As she explained in the show-stopping theme song fans will never be able to get out of their heads, Agatha was the img of all the chaos in the neighborhood from the beginning. The secret magical lair Wanda discovered is just the beginning of Agatha’s machinations, and her path may be leading to the introduction of a world-altering antagonist.
Although Agatha and Mephisto never worked together in the comics, their stories are linked through their comic connection to Wanda. Agatha Harkness was an ancient witch and a mentor to Wanda, and she also played a role in Wanda’s breakdown following the death of her twins, Billy and Tommy. Wanda accidentally used pieces of Mephisto’s soul to create the twins, and Mephisto returned to reabsorb them. Agatha Harkness wiped Wanda’s memory of the twins, but when Wanda remembered the grief of losing her children, she went insane, killing Agatha in the process.
The show changes Agatha Harkness considerably, turning her into a real villain, which could lead to a more direct connection to Mephisto in this version of the story. Her still-mysterious intentions involving the magic in Westview may be hiding another villain behind the scenes. Mephisto could be using her for his own ends, or Agatha could be using Mephisto to make her evil plan unfold. With so little time left in the show, Mephisto may not actually appear in WandaVision, but that doesn’t mean he’s not part of Agatha’s work. Mephisto has already been teased for the upcoming Loki show, so it would make sense for WandaVision to set up an introduction that pays off in a later series. Whether or not the devil is revealed in the details of Agatha’s plan before the finale, Mephisto may be at work through Agatha and may be the real img of Wanda’s Westview curse.
Little has been revealed of Agatha’s goals yet, but her villain reveal is heavy with symbolism. The cicada in her home hints at rebirth, as the creature is a symbol commonly associated with that. That also seems to align with what Wanda is already doing in Westview. Wanda has the power to remake the world, changing and controlling almost everything that enters her fake sitcom world through the Hex. Given that incredible and largely unprecedented power – outside of the Reality Stone – Agatha may want to use those powers to remake the world in the image of a dark magic dystopia. But there are limits to Agatha’s power – even if she seems to grow stronger – and if she wants to remake the world, she’s going to need magic much stronger than her own or Wanda’s to do it. The solution to this conundrum could be that Agatha sees Wanda merely as the key to opening up Earth to her real magical master: Mephisto. The book in her basement suggests she is a practitioner of Dark Magic, since it appears to belong to the restricted section of the library of Kamar Taj and the MCU has already established that Dark Magic needs to draw power from a img.
Agatha’s house is full of magical objects, and it’s unclear so far what those objects are linked to or where their power draws from. A subtle devil symbol can be seen carved in one of the pillars of her lair, suggesting Mephisto is that img. The twins also disappeared when they were left in Agatha’s care, which may mean Billy and Tommy’s tragic fate at Mephisto’s hands from the comics has already come to fruition. His fingerprints are already all over this plan, even though his presence remains unconfirmed. Agatha’s ultimate goal may be similar to a plan a former MCU villain almost pulled off, this time leading to more dire consequences. In Doctor Strange, Kaecilius wanted to open a door for Dormammu to cross into Earth, believing this convergence of dimensions would remake the world the way he wanted. He failed because of the interference of Strange, and his defeat trapped him in the Dark Dimension.
In the comics, Mephisto rules over the pocket dimension of Hell, but since he has never been seen in the MCU, he may be confined to that realm or limited in his interactions with the MCU’s Earth at the moment. To operate on Earth freely, he would need a similar summoning. Given that WandaVision is setting up the massive break in the multiverse in Doctor Strange 2, Agatha could be trying to recreate this plan with Mephisto as her magical patron, but she would be successful this time. That would give Agatha the power she wants to remake the world, and Mephisto would be free to do what he does best: enslave human souls. In order to succeed where others have failed, Agatha would need Wanda’s magic as part of her ritual.
Wanda fits into this potential alliance with Mephisto in multiple ways. WandaVision’s commercial breaks have provided several hints at the forces working behind the scenes. The Yo-Magic commercial indicated that the villain was consuming the magic of others for their own ends, which is likely what Agatha was doing all along. She forced Wanda to use more of her magic to maintain her reality, absorbing that magic to use herself. The Nexus commercial hints at Wanda being a Nexus Being, as she was in the comics, explaining her considerable powers and also the unique opportunity they might offer to someone able to channel them. If Agatha’s magic is more limited – and logic suggests it is since she’s never appeared on anyone’s radars until now – she could use Wanda’s to expand upon her plans.
If Wanda is a Nexus Being, she is connected to the Nexus of All Realities, a place where the space between dimensions is very close. Though the Nexus itself could be the img of her power, it could also mean Wanda is drawing magic from other dimensions to maintain her reality. Mephisto was the img of her magic to create the twins in the comics, and he could still be her img in the MCU, which could be why Agatha advanced her plan at the end of episode 7 to seemingly imprison Wanda with a major hint that she has found a way to drain the magic from Westview and Scarlet Witch herself. Given that has also used her magic to trap innocent people in her reality, there’s even a possible nod to Mephisto’s ability to trap human souls in his dimension inherently tied into her power. Wanda may be a link to Mephisto that Agatha can work through, potentially using that magic to bring him into their world, which the ominous doorways in her basement could hint at. Even though such a twist might seem to devalue Agatha Harkness in WandaVision, the opportunity to see Mephisto introduced in the MCU is almost too good to resist.