There have been many WandaVision, suggesting he could still potentially play a role in the finale of the series or in the future of the MCU. He is one of the most powerful beings in Marvel Comics and would be a major foe in the MCU. But could he defeat Wanda Maximoff?
The eighth episode of WandaVision revealed that Wanda is indeed the 'Scarlet Witch' and capable of power on a scale she wasn't even aware of. Wanda gave Thanos a run for his money, and would certainly defeat him in her current form. Would she be able to stop Mephisto?
Mephisto: He's Immortal
The biggest problem with Mephisto for any challenger is that he's immortal. As the analog for the Devil in Marvel Comics, he has existed for essentially all time. He claims to have been created with the Marvel Universe, and though he has been thwarted on many occasions by Marvel heroes, such as Thor, Silver Surfer, and others.
But he can't be killed. There appears to be a caveat, though. Mephisto once told Galactus he would exist so long as his dimension, Hell, did, suggesting destroying it would destroy him.
Scarlet Witch: Can Harness Magic Of Others
Mephisto's powers are rooted in large measure in truly powerful magics. His main problem with Wanda is that she can harness the magic of others to make herself even more powerful. She's done this a few times in the comics, notably getting a huge power boost after being attacked by Morgan Le Fay, one of the most powerful magicians in Marvel Comics.
Wanda parlayed this power to truly devastating consequences, ultimately altering reality on a global scale in the 2005 event House Of M.
Mephisto: Energized By Evil Energy
Wanda isn't the only one who gets a boost from the magic of others. One of Mephisto's many powers is to harness the evil energy of other beings. This gives him even more power, particularly outside of his dimension. In Fantastic Four #277, Mephisto harnesses the evil energy of the alien Dire Wraiths.
The Dire Wraiths are an offshoot of the Skrulls in the Marvel Universe, but they also have another unique connection to a mostly forgotten '80s toy. They were created as the villains for Rom The Space Knight in the first issue of his Marvel comic book.
Scarlet Witch: Can Change Reality With A Word
House Of M is one of the major comic book influences on WandaVision and it's easy to see why. Wanda uses her vast power in chaos magic to alter reality so that her sons, Billy and Tommy, still exist. When this fantasy is disrupted by the X-Men, she lashes out and changes reality so that only 200 mutants - out of tens of thousands - still exist.
Wanda's ability to alter reality on a molecular level makes her a formidable opponent for anyone, including Mephisto. Outside of his own dimension, he would be at the mercy of her power the same as anyone else.
Mephisto: Within His Dimension, He's All-Powerful
Wanda can alter reality, but it's unclear if she would be able to influence the dimension of Hell. Mephisto is all-powerful there. He is able to configure and restructure the nature of Hell at his whim, as he showed in his very first appearance in Silver Surfer #3 in 1968.
If he is destroyed in any other realm, he automatically regenerates in Hell, suggesting the dimension could feature some of the same restorative abilities if it were to be threatened by outside forces.
Scarlet Witch: She's A Nexus Being
Wanda is one of the most powerful beings in the Marvel Universe. In fact, she's truly singular. She is a Nexus Being, a living incarnation of a dimensional gateway between all realities. There is only one such being in each universe, which is what makes her so unique and so powerful.
Wanda's access to other dimensions makes her truly unpredictable and especially dangerous to Mephisto because she can access the dimension of Hell directly, and take the fight to him. Wanda's status as a Nexus Being seems to have been teased in WandaVision through the commercial for "Nexus" in episode seven.
Mephisto: Master Manipulator
There are many ways Spider-Man. Mephisto was the architect behind the infamous One More Day storyline in which Peter Parker and Mary Jane's marriage was erased from history. Mephisto manipulated Peter Parker to trade it for the life of Aunt May.
Mephisto's manipulations are the core feature of his actions in the Marvel Universe. He often corners people in Faustian bargains to get what he really wants. Wanda would be equally susceptible, a victim of grief and trauma who just wants to find some peace.
Scarlet Witch: Her Magic Is Unpredictable
Wanda is one of the most powerful - if not the most powerful - practitioners of chaos magic in Marvel Comics. Chaos magic allows s to manipulate, warp, and reconstruct the very fabric of existence and reality. Wanda is simply unpredictable in the application of her power, as witnessed in Westview.
This makes her incredibly threatening to anyone, even Mephisto because there is no anticipating her attacks. Her power is rooted in the ancient and dark magic of one of the Elder Gods, Chthon, a being as old and powerful as Mephisto. This alone puts her on equal footing with him.
Mephisto: He Fought Galactus To A Stalemate
A great example of Mephisto's power is his scorecard against one of the most powerful cosmic beings in the Marvel Universe - Galactus. Galactus once invaded Hell and set about trying to consume it as he does planets, in order to destroy Mephisto.
Mephisto basically made his dimension indigestible and Galactus was forced into a stalemate. He eventually withdrew. This signaled the extent of Mephisto's power, placing him on the same level as Galactus, or arguably ahead, and in very rare company.
Scarlet Witch: She'll Rip His Heart Out
Wanda's power clearly puts her on a level playing field with Mephisto - she's nearly god-like in her ability to alter reality. She might get the edge for her capacity for anger. Wanda often displays a cruel streak when wounded or confronted, as Monica Rambeau found out a few times in WandaVision. But it's Ultron who really shows how angry she can be.
In Avengers: Age Of Ultron, Wanda rips Ultron's heart out after the death of her brother, Quicksilver. This doesn't kill him, as he escapes to another drone, but it shows that she will go to lengths others won't to protect herself or avenge her loved ones.