'Loki' director debunks Mephisto theory after fans think the show hinted at him in the opening episode

• Warning: Spoilers ahead for "Loki" and "WandaVision."
• Fans think they saw Mephisto, Marvel's answer to the devil, in a stained-glass window in "Loki."
• But director Kate Herron said it's just a "weird coincidence" and it's actually a reference to Loki.

The Marvel Cinematic Universe is prone to all sorts of weird and wonderful fan theories, some of them more convincing than others.

"WandaVision" spawned more fan theories than most MCU projects, with one of the most passionate and popular theories revolving around the inclusion of Mephisto, Marvel Comics' answer to the devil.

Unfortunately for those aboard the Mephisto train, that theory never left the station as "WandaVision" wrapped with only a billboard hint to the presence of the Marvel demon. He was never introduced or officially referenced in anyway.

But now, the Mephisto theory is back after fans think they spotted him in the opening episode of "Loki."

Warning: Spoilers ahead.

We are introduced to Owen Wilson's Agent Mobius, an agent of the Time Variance Authority, who is trying to track down a time criminal. He begins his investigation in a church, where he talks to a little girl and tries to find out who murdered someone in the sacred building.

The girl points to a stained glass window that features the devil, which seems like a very obvious reference to Mephisto.

"Don't worry, that devil's afraid of us," Wilson's Mobius says. "We're going to take care of him."

But Mephisto fans' excitement over his possible inclusion was cut off by Kate Herron, the show's director, who already shot down this theory.

In an interview with Entertainment Tonight on June 7, Herron said: "It's honestly just a super weird coincidence. Like, it's genuinely a reference to Loki - the horns, he was cast out of heaven, that's what it's a reference to."

"We filmed that a long time before. I think 'WandaVision' must have been in post when we filmed that. I did see all the stuff about that online and I was like, 'Oh, this is going to be interesting.' But no, it's more relevant to the themes of our show and it's not a nod to that character."

While Herron's comments might not completely rule out Mephisto's involvement in the MCU - she could just be playing coy to keep the surprise under wraps - it seems pretty likely that this particular reference has nothing to do with Mephisto.

We'll have to wait and see if Mephisto pops up in "Loki" or any future MCU project down the line. But for now, Herron's show has bigger fish to fry: the potential creation of the multiverse.