After "WandaVision" Episode 5, Agent Jimmy Woo is gonna need a bigger whiteboard for all the new questions. Here's a Q&A exploring those issues. (Spoilers ahead!)
Q: Why does Darcy Lewis (Kat Dennings) call Wanda's superpower effect a hex?
A: Because that's what Wanda's power was called when she was introduced in "X-Men" comics in 1964. Back then she could cause catastrophic accidents, or hexes, with a gesture. But Wanda grew in power and scope over the years to the Scarlet Witch of today, who can manipulate reality. On the show, they explain it away by pointing out that Wanda's power manifests itself in hexagonal shapes.
Q: Why wasn't Pietro played by Aaron Taylor-Johnson in "WandaVision," as he was in "Avengers: Age of Ultron"?
A: That's a very good question, which raises many more. As noted, the Pietro in the Marvel Cinematic Universe was played by Taylor-Johnson, who died in "Age of Ultron." Another, wholly unrelated Pietro existed in Fox's X-Men movies, due to the co-ownership mentioned above, played by Evan Peters. Since Wanda's original Pietro is dead, somehow the living version we know about from an unrelated movie series was substituted instead.
And it's not just a recast — both Vision (Paul Bettany) and Darcy failed to recognize this Pietro. But the audience did, and it's a jaw-dropper. See, Marvel never could mention or use mutants, due to Fox owning the X-Men rights. Until now. Pietro is not only a character from another universe, he's the first mutant in the MCU. Won't the X-Men be close behind?
Q: Wait, why couldn't Wanda resurrect her actual brother? She brought Vision back to life.
A: That's another very good question, which we will have to wait for the show to reveal. In "Special Episode," Wanda explains to her boys that she can't, in the words of one of the twins, "fix death." So Sparky the dog remains dead. But what about Vision? Well, that's completely unexplained, especially as we see him briefly as he truly appears in another episode, as a gray-skinned, dead-eyed corpse with a hole in his head.