WandaVision Writer Reveals the Grief-Stricken Reason Why Evan Peters Replaced Quicksilver WandaVision Writer Reveals the Grief-Stricken Reason Why Evan Peters Replaced Quicksilver Marvel Studios' Disney+ debut of WandaVision blew every theory about X-Men's inclusion in the MCU out of proportion. WandaVision and the upcoming Black Widow has finally cleared the speculations behind Evan Peters' casting as the Hex incarnation of Pietro Maximoff aka Quicksilver. WandaVision kick-started the MCU's Phase IV with a unique and different approach and its first season bid adieu with an emotional climactic sequence and a flabergasting post-credits scene. Throughout its run, WandaVision introduced us to new characters, new storylines, and one mind-blowing cameo.