This WandaVision article contains spoilers.
Wandavision has arrived, and with it, a whole slew of new Marvel characters join the MCU. Probably the most interesting, and the one with the most implications for the story of the next phase of the Marvel Cinematic Universe, is Wanda and Vizh’s neighbor, Agnes (Kathryn Hahn). The strange couple’s next door neighbor is actually Agatha Harkness, and her presence here bodes ill for Wanda’s mental health.
Harkness has a somewhat complicated history [editor’s note: she’s old enough to remember Atlantis sinking, go on with “complicated”], par for the course for anyone mentoring a reality manipulator. But reality warpers are something of a specialty for her – her first appearance in the comics wasn’t as part of the Scarlet Witch’s supporting cast. No, she was originally Franklin Richards’ (the son of the Fantastic Four‘s Reed Richards and Sue Storm) governess. Richards, the canonical culprit behind Marvel Time, was a newborn when she was brought in to care for him, and she did so effectively, saving the boy (and his family) on more than one occasion while she was responsible for him.
Marvel’s first family eventually learned more about her origins: she was an extremely old member of a colony of witches that started in Salem, then migrated to Colorado after their persecution at the hands of a gang of vicious Massholes. Agatha’s estranged son, Nicholas Scratch, eventually outed her to the Fantastic Four by kidnapping her and Franklin and bringing them to the colony. He was defeated and banished, but not before the Four and a group of Agatha’s grandkids – called the Salem’s Seven – threw down.
That was when she left the service of the Richardses and became Wanda’s mentor. Agatha taught Wanda how to use her powers more effectively and showed her that her natural probability altering skills were actually magical in nature. Wanda and Vision married, then came into conflict with a resurrected Salem’s Seven to save Agatha.
Ultimately, they failed: Agatha was burned at the stake by her grandkids. But that battle helped convince Wanda to start a family with Vizh, so she channeled the mystical energy running loose from their fight to make herself pregnant with Vision’s child. What an amazing sentence to write. And it gets better: some of that energy intermingled with loose shards of Marvel’s preeminent Satan analog Mephisto’s soul.
What followed was a brief period of happiness for Wanda and Vision where they got to live a happy life being West Coast Avengers and raising their kids. Unfortunately, that bliss didn’t last: Master Pandemonium, an Avengers villain with demons for arms and legs, kidnapped Wanda and Vision’s twin children Tommy and Billy, and absorbed them into himself, whereupon their Mephistic provenance was revealed, making Wanda super pissed, and an inexplicably resurrected Agatha very concerned. So Agatha wiped Wanda’s mind of any memory of her kids.
Agatha went on to mentor Wanda for years, revealing to readers just how powerful the Scarlet Witch actually is, and thus her reasoning for wiping her mind: Wanda can alter reality on a quantum level. Uncontrolled grief would be very difficult to deal with. Agatha’s mentorship shows that, while her methods were bad, her heart was in the right place, which makes it all the more tragic when Wanda discovers the truth and murders Agatha in Avengers: Disassembled. But dont worry: she gets better.