Warning! Spoilers ahead for Marvel's WandaVision Episode 5
Episode 5 of Marvel's WandaVision ends with a major cameo, and it carries some big implications for the future of the MCU. Right as Vision was confronting Wanda about what she's done to him and the town of Westview, someone rang their doorbell. Answering the door, Wanda is shocked and surprised to see a man claiming to be her brother Pietro, otherwise known as Quicksilver.
However, not only is this a shock because Pietro Maximoff is supposed to be dead, but this is not a Pietro Wanda recognizes, and it's not the same actor seen in Avengers: Age of Ultron. Instead of actor Aaron Taylor-Johnson playing Quicksilver in this episode of WandaVision, Evan Peters is standing at the door as Pietro, acting like everything should be normal, having shown up to surprise his sister after having been gone for some time.
While this might be confusing for some viewers (even SWORD's Darcy Lewis is confused as to why Wanda recast her brother), there is an explanation and it's incredibly significant: Evan Peters is playing this new Pietro because he played Quicksilver in FOX's X-Men films and separate universe of Marvel mutants. Here's a breakdown and explanation of both versions of Quicksilver, why the X-Men's version of Pietro has been brought to Westview instead of the one Wanda knows, and what this means for the rest of the series as well as the MCU's future going forward.
Different Marvel Quicksilvers Explained
Within the span of a year between 2014 and 2015, two different live-action versions of Marvel's Quicksilver were introduced and depicted on screen. One was introduced in 2014's Scarlet Witch's dual status as Avengers and X-Men characters in Marvel Comics, their film rights were split between Disney and Fox respectively (though Disney now owns the rights to the X-Men as of 2019).
FOX's version of Pietro was classified as a mutant, who eventually ed Charles Xavier's school for the gifted and team of X-Men, and was also secretly the son of the villain Magneto. In contrast, the MCU's Quicksilver and his sister Wanda were Sokovians who lost their parents. Seeking to be empowered to fight for their country, they volunteered to be experimented on by Hydra, who activated their powers with the Mind Stone (the same stone that brought Vision to life).
While Pietro and Wanda initially ed forces with Ultron to get revenge on Iron Man, they soon realized his true intentions to destroy all life on Earth and they quickly defected, becoming Avengers themselves. However, Aaron Taylor-Johnson's Quicksilver would end up giving his life to defeat Ultron, making the Avengers sequel his only appearance in the MCU, while Scarlet Witch would go on to have multiple appearances in the MCU, including her titular role in Marvel's WandaVision.
Why Wanda Brought The X-Men's Quicksilver To Westview
As previously mentioned, Wanda appears to be shocked at the end of WandaVision's fifth episode, indicating that it was not her intention to bring Pietro back at all, let alone a Pietro she's unfamiliar with. However, recent episodes (including this one) have made references to Wanda's brother, such as when Wanda revealed that she had a brother to Geraldine/Captain Monica Rambeau, or when she talks to her sons Tommy and Billy about Pietro. Instead of telling her children that he died, she tells them that he was simply "far away from here".
Additionally, Episode 5 focuses quite a bit on death and resurrection, which could be telling as to why Evan Peters' Pietro has been brought to Westview and not Wanda's own brother. When Billy and Tommy's dog Sparky dies, they ask Wanda to bring him back to life. However, Wanda reveals that she can't. While SWORD's findings have lead them to believe that Wanda took Vision's remains and reanimated him, this is probably because he's not human and is in fact a synthezoid. When it comes to the living (non-artificially), resurrection seems to be a limit to Wanda's power.
It seems likely that Wanda's own subconscious and recent thoughts of Pietro is what brought her brother to Westview. However, due to his death and her inability to bring him back to life, she may have inadvertently brought the X-Men universe's Pietro to Westview instead, potentially pulling him from across the Multiverse.
What This Means For The Future Of WandaVision and the MCU
As far as what the arrival of this other Pietro means for the rest of WandaVision, it's as of yet unclear. Pietro has appeared in the style and personality not unlike Fonzie from Happy Days, indicating that he's been assimilated into the town of Westview just like everyone else. At the moment, he probably doesn't who he is and where he comes from, only knowing that he's the long lost brother of Wanda who's come to town for a visit.
As far as the long term is concerned for the MCU's Spider-Man film). As such, this new Quicksilver seems like he could be a big reason as to why this series and the Doctor Strange film will be so connected. If Wanda can transport people from across the Multiverse - as is the implication with Pietro - her powers would be off the charts and could likewise cause some major problems to reality that would no doubt necessitate the Sorcerer Supreme's involvement and assistance.
Additionally, the rights to the X-Men franchise are now in the hands of Marvel Studios, and Evan Peters' Quicksilver appearance in WandaVision could be the perfect bridge to finally bring the concept of mutants and the X-Men to the MCU at large. While this is all just conjecture and theory at the moment, it seems very likely all things considered. In any case, fans will no doubt learn more as Marvel's WandaVision continues on Disney Plus.