The identity of the Joe Locke's Agatha All Along character, known simply as 'Teen' thanks to a magical sigil that blocks him from speaking his name aloud, is widely believed to be none other than Billy Kaplan/Maximoff, one of the twin sons of Wanda Maximoff, the Scarlet Witch, and the Vision.
Known as Wiccan in comics as one of the founders of the Young Avengers, Billy Kaplan (the surname of his adoptive parents) is a mutant with an innate spellcasting ability akin to his mother Wanda Maximoff, who has also mastered the art of sorcery.
But that's just the tip of the iceberg of Billy's comic book history, and it's saying nothing of his twin brother Speed AKA Tommy Shepherd, who appeared alongside Billy in WandaVision and Doctor Strange in the Multiverse of Madness.
If 'Teen' is indeed Billy Kaplan/Maximoff, it's entirely likely that Tommy's still out there somewhere too, and that both of them could be recruited to Kamala Khan/Ms. Marvel's burgeoning Young Avengers team.
So let's dig into the comic book history of Billy and Tommy Maximoff to see exactly what Billy's potential return could spell for the rest of Agatha All Along, and for the MCU to come.
Who are Billy and Tommy?
In comics as in the MCU, Vision and Scarlet Witch developed a complicated romance culminating in their wedding, which led, naturally, to Wanda's desire to build a family and have children – a prospect stymied by Vision's lack of human reproductive material (it's been implied he has human-like anatomy, so sex is possible but actual reproduction isn't).
Enter Agatha Harkness, a powerful witch who has served as Wanda Maximoff's mentor over the years after first being introduced as a nanny for Franklin Richards in Fantastic Four. Though she'd later take Wanda under her wing, the pair first met in a noted haven for witches, New Salem, Colorado, facing down a coven of magical villains named Salem's Seven; a group comprised of Harkness's grandchildren, fathered by her son Nicholas Scratch.
Many aspects of this mythology, including Salem's Seven and Nicholas Scratch, have now been incorporated into the MCU thanks to both WandaVision and Agatha Harkness' current Agatha All Along streaming series.
When Salem's Seven are defeated after burning Agatha Harkness at the stake, she enters an astral form and imbues Wanda with massive amounts of magical energy from the Seven – magical power Wanda uses to form her twin sons William and Thomas, who become the consummation (of sorts) of her marriage to Vision.
Though William and Thomas are infants and appear as human children, just as in WandaVision, they are not actually flesh-and-blood in comic books. Instead, they're magical manifestations of part of the soul essence of the demonic Master Pandemonium, one of the many guises of the devilish Marvel Comics villain Mephisto (who was namechecked in an episode of Agatha All Along), working through a human agent.
Unfortunately, the timing of this revelation couldn't have been worse for Wanda, who was still reeling from the corruption and destruction of her husband the Vision, who had turned evil, tried to conquer the world, and rebuilt as an emotionless husk. All of this is too much for Wanda, whose sanity is threatened by the series of events.
To end the madness, Agatha Harkness reabsorbs the twins back into Master Pandemonium's soul, and erases their memory from Scarlet Witch's mind. But the memory of her children returns when Wanda is rescued from the real culprit behind the entire thing – Immortus, one of the many guises of the time-traveling Kang.
Years later, Wanda finally loses her grip on reality and attacks her own teammates, the Avengers, leading to the (temporary) deaths of Hawkeye, Vision, Ant-Man, and more in a story-arc titled Avengers: Disassembled. And of course, that story led to House of M, an even more complex reality-bending story that was referenced in WandaVision.
Who are Wiccan and Speed?
The defeat of Mephisto and Immortus and the disappearance of the magically created William and Thomas wasn't the end of the twins' story. The human portion of their souls, created from Scarlet Witch's power and Mephisto's dark magic, were reincarnated as the human children Billy Kaplan and Tommy Shepherd who, despite being born and raised separately, each developed mutant powers.
Billy is able to alter reality through spellcasting like his mother Scarlet Witch, and Tommy is able to run at super-speed like his uncle Quicksilver, Wanda's brother from comic books who perished in the MCU in Avengers: Age of Ultron and who had a more central role in Fox's later X-Men films, and who, of course, had an off-beat cameo that mashed both incarnations together in WandaVision.
Taking the codenames Wiccan and Speed, Billy and Tommy reunite as Young Avengers, teen heroes who stepped in following the dissolution of the original Avengers in the aforementioned Avengers: Dissassembled and who have connections to the classic team.
As part of the Young Avengers, Billy and Tommy discover their true heritage as the reincarnated children of Vision and Scarlet Witch, and embark on a quest to find her, encountering Quicksilver and Magneto – who was then believed to be Scarlet Witch and Quicksilver's father (it's still kind of up in the air in comics, with many retcons and changes to their family history over the years).
They all discover Wanda is hidden in Latveria with Doctor Doom, who plans to marry the now-amnesiac Scarlet Witch as part of the culmination of a long-term plan to manipulate her and harness her reality-altering power – a scheme that goes all the way back to Avengers: Disassembled, which is revealed to have all been influenced by Doctor Doom's dark magic as part of his plan to control Wanda.
Wanda and Wiccan are reunited, with Wiccan using magic to restore Wanda's memories as well as confirm that he is truly her reincarnated son. The two reluctantly agree to help Doctor Doom cast a spell that Wanda intends to restore the powers of the mutants she depowered on M-Day, in the wake of Avengers: Disassembled and House of M.
But Doom seizes her reality powers instead, forcing Patriot of the Young Avengers to interrupt the ritual, leading to the death of his teammate Stature (as in Cassie Lang, Ant-Man's daughter who has appeared in the MCU alongside her dad as the hero Stinger, her later codename), but not before she's able to use Iron Lad's time-travel technology and Wanda's powers to rescue her father, Scott Lang, from his death in the past.
With Cassie dead (she, too, got better) and the Vision destroyed in the final battle of the Avengers against Doctor Doom, the Young Avengers resolve to move forward.
Notably, since then, Wiccan (Billy) has gone on to marry his longtime love interest and Young Avengers teammate Hulkling, and become the official consort of Hulkling's combined Kree/Skrull empire.
Billy and Tommy in the MCU
Billy and Tommy have both appeared in the MCU, starting with WandaVision, in which they both rapidly grew up, aging more with each episode. They did eventually develop versions of their comic book powers, but, as in comics, they were both revealed to be not actual flesh-and-blood children, but manifestations of Wanda's reality-altering magic.
And tragically, just like in comics, they faded away at the end of WandaVision, leaving Wanda Maximoff bereft. This in turn leads her to use the sinister magical book known as the Darkhold to traverse realities in an attempt to take versions of Billy and Tommy from an alternate world in the Multiverse and raise them as her own in Doctor Strange in the Multiverse of Madness.
This then leads directly to Agatha All Along, which picks up Agatha Harkness' journey after the death of Wanda Maximoff, and to the introduction of 'Teen,' who is heavily implied (and widely believed) to be a version of Billy Maximoff who will potentially become Wiccan.
We still don't know if that's the case (there's always room for a swerve in the MCU) and it also leaves questions about where Tommy might be. But the likely potential that 'Teen' is Billy Maximoff leads to some big implications about what he might actually be seeking in his journey down the Witches' Road like, for example, possibly even the resurrection of his mother, the Scarlet Witch.
There's also the strong possibility that Agatha All Along may end with Wiccan being recruited into Ms. Marvel's Young Avengers, which officially started forming in the post-credits stinger of The Marvels with the recruitment of Kate Bishop/Hawkeye.
We'll learn more as new episodes of Agatha All Along premiere Wednesday evenings on Disney Plus.
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