MCU viewers were looking everywhere for A Big Bad Villain to pop up in WandaVision, sometimes reading way too far into things; and many were absolutely sure Mephisto would make an appearance. But nothing ever came of it all. The hilarious end result is that "Mephisto sightings" have now become a running gag among people watching the Marvel series', lol. That suspicious-looking guard? "Mephisto!" The devilish figure in the stained glass? "Mephisto!" That bug over there? "Mephisto, confirmed!" It's pretty funny watching everyone poke fun at it and themselves, lol.