‘Agatha All Along’ stripped of its record as MCU fans realize major Marvel villain has secretly been haunting the Avengers for the past 12 years

Marvel fans lost their minds when Agatha All Along episode 3 went and confirmed something we’ve been waiting for since the Multiverse Saga began — confirmation that none other than Mephisto exists in the MCU. The satanic supervillain has yet to appear in the red flesh just yet, but Jennifer Kale’s reference to an “agent of Mephisto” in the Disney Plus show’s third episode at last assures us he’s lurking around somewhere in the Sacred Timeline.

Mephisto fan theories have abounded throughout the MCU’s Phases Four and Five, and we can blame WandaVision for that, but the Hell-Lord never actually got a name-check in the franchise until now. Or did he? In the wake of Agatha‘s Mephisto mention, eagle-eyed fans have realized that Mephisto may have been hanging around the MCU… all along. Ever since 2012’s The Avengers, in fact!

Wait, when did Mephisto show up in The Avengers?

As pointed out on X by @NerdGamer91, Mephisto’s very first namedrop appeared in The Avengers a full 12 years ago, but this has hardly been noticed until now. When Nick Fury recruits Steve Rogers into his Avengers initiative, he hands Cap some files to bring him up to speed on the Tesseract. If you pause the scene as Steve is rifling through the pages, you can see that the write-up includes a reference to Mephisto. While this was no doubt intended as a subtle prop design joke, the fact that it means Mephisto’s name appears on screen for the first time in the MCU earns it an unexpectedly greater significance in the grand scheme of things.

The only hitch is that a closer inspection of the text in question reveals it’s dated rather badly and might not necessarily be considered canon anymore. “Mephisto has postulated that the Cubes are hosts to a semi-sentient will and that, even in Cube form, they can choose how they want to be used and to deny certain wishes,” it reads.” Mephisto also has proposed that a billion-sentient universally-linked wills could overcome this problem and that the Cubes could be as powerful as the Infinity Gems.

Apart from the curious fact that Mephisto is apparently a source of intel for S.H.I.E.L.D. — they have informants everywhere, I guess, even hell — this text indicates that the Tesseract is a separate construct from the Infinity “Gems.” It wasn’t until after The Avengers came out that Marvel not only decided to rename the Infinity Gems the Infinity Stones, but also confirmed that the Tesseract was one of the Infinity Stones itself.

We’re still not entirely sure if his Agatha mention will lead to an actual appearance from him or not, but thanks to both that name-drop in episode 3 and this rediscovered reference in The Avengers it’s becoming clearer that Mephisto has been stalking the MCU from the shadows for the longest time, perhaps even keeping an eye on Earth’s Mightiest Heroes — and its most powerful witches — as he waits for the right moment to make himself known.

Exactly when that right moment will be is somewhat unknown at present. Reports once indicated that Sacha Baron Cohen was secretly cast in the role for a surprise appearance in the upcoming Ironheart series. However, that show has been so thoroughly redeveloped since then that no one currently knows how much of the original plan survives. If he has been insinuating himself in the MCU since the Battle of New York, however, Mephisto finally entering the fray to fight the successor to Tony Stark’s legacy would actually make a fair amount of sense.