Agatha All Along finally confirms [SPOILER] is Marvel's next big villain

Ever since the beginning of the Multiverse Saga in 2021, Marvel Cinematic Universe fans have been talking about one person. It's not classic MCU heroes like Iron Man or Captain America, or Phase Four staples like the Scarlet Witch, Wong, Spider-Man, or Doctor Strange. No, it's the one person we've all been waiting to appear. And, rather ironically, the one person who has yet to actually appear.
We are, of course, talking about Mephisto.

Marvel Studios' first Disney Plus series WandaVision had fans convinced that the character would be involved, both due to his history with Agatha Harkness and the Scarlet Witch, and the fact that there were a number of nods and references that could have led to his arrival. When that didn't happen, they were convinced it would happen in Loki, in Doctor Strange in the Multiverse of Madness, in What If...? and so forth.

Now, three years later, in WandaVision spinoff series Agatha All Along, we have finally gotten our first direct reference to the character.

Agatha All Along references Mephisto in episode 3

The third episode of Agatha All Along, "Through Many Miles Of Tricks and Trials", finally references none other than Mephisto, and it's really quite the namedrop, particularly as it comes right as Teen begins to question his allegiance to Agatha.

During the first of the Trials that the coven encounters on the Witches' Road, Jennifer Kale has a conversation with Teen about the infamous witch. Though Teen is excited to be working alongside her on their quest to get to the end of the Witches' Road, Jennifer warns him to watch his back as Agatha traded her own son, Nicholas Scratch, for the Book the Damned, a.k.a. the Darkhold. She follows that up by saying that nobody knows what happened to Nicholas since, claiming that some say he became a demon, while others say he might be an agent of Mephisto.

It's almost a blink-and-you'll-miss-it namedrop, but it's there and it's a major one. For years, fans have been longing for the arrival of Mephisto; predicting it, even, with the hopes that he might turn up in WandaVision, in Loki season 1, in Doctor Strange in the Multiverse of Madness, or in Werewolf by Night. But it never happened, and as a result of that, it became something of an inside joke among Marvel fans, as they playfully suggested that Mephisto was responsible for just about any mystery in the MCU because his name had come up so many times before.

But now we know that's all leading somewhere, as Agatha All Along has confirmed that the character exists in the world of the MCU. And this is more important than we may know at this point in time, both because of the rumors involving this show, and the rumors about the character's arrival in another.

Agatha All Along has teased fans with the possibility of Mephisto already. As the show is a spinoff of WandaVision (the series where all of these Mephisto rumors started), it's the perfect place for a potential debut. Fans haven't been playfully suggesting Mephisto as a villain for this one; they have been legitimately suggesting him as a villain. His presence here makes sense.

There has been speculation that the mysterious Teen has a connection to Mephisto as well. The character is currently under the influence of a Sigil, which means he can't reveal his name to Agatha (or anyone around him, apparently) as, whenever he attempts to, a large jagged letter appears across his mouth, blurring out the sound of whatever he says. Some fans think the Sigil is in the shape of a W, referencing the Scarlet Witch Wanda Maximoff. That would line up, as the character is believed to be Billy Kaplan, Wanda's son. On the other hand, there is speculation that the Sigil is in the shape of an M, having fans convinced that it's a reference to Mephisto.

In the pages of Marvel Comics, Mephisto is a devil-like figure who is known for his ability to manipulate others and rework outcomes and events to benefit himself. He's immortal, a shapeshifter, and unbelievably durable, making him virtually impossible to defeat. He's also one of Marvel's most powerful villains. And his arrival in the MCU could indeed open the door for the franchise's more supernatural era.

There have been rumors that Mephisto was on his way to the MCU and that it might start in Agatha All Along. Those rumors claim that the character will be played by Sacha Baron Cohen and that he'll have a more significant role in next year's Ironheart. We'll have to wait and see if that pans out to be true, but one thing is for sure: This time, it might actually be Mephisto all along!