The latest WandaVision episode cleared a lot of questions we all had regarding the Hex, the sitcom-styled events, Vision's resurrection, and of course, the origin of Agatha Harkness. But there was one thing special about the episode, which put Elizabeth Olsen's Scarlet Witch among the prominent super-beings within the MCU. And that was the experiences of her past. Be warned, there are BIG SPOILERS ahead.
Previously On, the allegorical title to the episode in context with its plot, takes us back on a recap of Wanda's life since the very day when Stark Industries' missile changed her and Sokovia's fate. And in one of those scenarios, the episode may have left us a hint to the origin of her powers. And no, it wasn't the Mind Stone.
Hint At Wanda's Powers
In the episode, Agatha forces Wanda to revisit the day her parents were killed by a missile that struck her house. It starts as a happy moment where the family is sitting in joy, watching The Dick Van Dyke Show. Suddenly a missile instantly kills her parents and destroys her house. A second missile, however, fails and the kids, Wanda and Pietro, are saved. This is the story Pietro narrates to Ultron in Avengers: Age of Ultron. If you remember, Pietro tells Ultron how he and Wanda waited for the second missile to go off and kill them for two days, but the missile never went off, thus, saving those kids.
WandaVision may now have hinted why that missile never blew up. The kids believe that the missile was defective, but Agatha has revealed what could be the true reason. In the episode, as Wanda and Pietro, as kids, stay under the bed with the missile right on their face, Wanda puts her hand out and tries to perform some telekinesis move to stop the missile from going off. But before anything could be confirmed, Agatha pulls her back to present.
Agatha claims that it was Wanda who stopped the bomb from going off. While Wanda fixates that the missile was defective, Agatha says that she used the Probability Hex. Since Agatha is more interested in learning about what power drives Wanda to create Westview's anomaly, she doesn't argue with Wanda much over it. In the comics, Probability Hex is a term for Tychokinesis, a power that allows one to manipulate and control probability and luck. As per Agatha, Wanda used this Hex and decreased the chances of that bomb going off, thus saving both her and her brother.
But Wanda never received her power until her young adulthood. It was during the experiments H.Y.D.R.A and Strücker conducted with the powers of the Scepter (it wasn't known then that it housed the Mind Stone) on Wanda and Pietro. Then how come she was able to perform Tychokinesis as a kid?
Wanda Is A Mutant?
In the comics, both Wanda and Pietro are children of supervillain Magneto and his wife Magda. They inherit mutant genes from their father, and hence, their power comes from birth. In the MCU, Marvel earlier had to change the origin story of Wanda and Pietro to avoid copyright clashes with Fox Studios, who at the time Age of Ultron came, held the rights to Magneto and other X-Men. And hence, they were given Sokovian heritage and ancestry and were added to the Avengers.
But now, with Disney's acquisition of Fox, the rights to X-Men, the mutants, and Magneto himself has reverted to Marvel Studios, which is a subsidiary of The Walt Disney Co. And adding Magneto's presence in the MCU in retrospect this way would prove that Wanda is a Mutant.
Theory: Wanda's Mutant Heritage
The theory is that both Wanda and Pietro are Magneto's kids. And as in the comics, their mother was estranged from Magneto, and she left her kids in the care of Romani parents. Maybe, Oleg and Irina Maximoff are adoptive parents to the twins, and they have carried those powers hidden since birth. This is possible for Marvel Studios to achieve, who has already established Carol Denvers' character entirely in retrospect to the events that have already occurred in the MCU.
This would also explain, how only Wanda and Pietro were the two people who survived Strücker's experiments, while others died. Even during the episode, we see Wanda being exposed to the power of Mind Stone, but she embraces it strongly and just faints out. The Stone just probably amplified the powers she had instead of killing her. It just provides all the proof that Wanda already had mutant powers, and with the experiments, her powers got stronger and made her more invincible.
Marvel's Idea of Adding Mutants to the Bigger MCU
As stated, Marvel has previously established multiple plotlines in retrospect, through flashbacks, or just by giving nods to details from previous movies. Possibly, Marvel would do the same to Wanda and Pietro as well. Evan Peters has already made an appearance as Quicksilver (he portrays the character in the X-Men franchise). Besides, in a previously altered post-credit scene from Iron Man, Samuel L. Jackson's Nick Fury addressed that he was already dealing with "radioactive bug-bites and assorted mutants", and now he has another problem. Meaning, Marvel always had planned MCU's future having Mutants in mind, and probably have always kept a storyline ready to execute whenever they are ready to incorporate them within the MCU.
Given that the copyrights are in their favor, and they already have a lot of wide-area to introduce them, with the multiverses bursting out of the wind, this probably the best time to have the gifted ones into the Marvel Cinematic Universe.