Marvel fans have been anticipating the debut of the demonic villain Mephisto in the MCU for years now, with speculation originally ramping up with WandaVision, which came and went without an appearance. Now that WandaVision's sequel series Agatha All Along is streaming, fans are once again searching for signs of Mephisto, especially in Aubrey Plaza's mysterious character Rio Vidal, who is expected to have a big reveal later in the season.
Mephisto may be one of Marvel's most iconic, enduring villains - and that's no surprise considering he's based on the archetype of the Christian devil, pretty much the most iconic 'villain' in religion, folklore, and in some cases, even as a metaphorical force in world history.
