So, in Agatha All Along, the characters who end up closely paralleling each other and being crucial for each other's arcs, are the characters who exchanged brooms during the hexenbesen ritual.
So, let's look into them one by one:
1) Agatha Harkness & Rio Vidal (“Out of Death, Life.” || “She is my scar.”)
First of all, let's get the obvious out of the way. Agatha and Rio, the ultimate push and pull. Tied together eternally by the strings of fate in a way that is almost codependent. Agatha—the maiden—romanticised death. Death is erotic, artistic, beautiful to the maiden. Death is comforting. Death cradles her. Death rescues her from her mother's cruelty. Death loves her. Agatha—the mother—views death as any mortal would. Death is terrifying, vile, evil. It chases her as she ages. It threatens to take he son, her heart. Death is ugly. Death is uncomfortable. At best, death is a means to an end. A necessary evil, for the sake of survival. For Agatha–the crone—death is a part of life. Death is transformation. Death is the end of a cycle. Death requires acceptance. Death is the natural order of all things. Death is everything at once and it is not to blame—but maybe she still is.
And to Death, Agatha her scar. She's a representation of everything she can't have: she can't have love, or a family... Because the one time she dared to try, her son was a stillborn—out of death, life. The one time she loved, so deeply that it planted a pain deep within her chest, a heart of obsidian—she was met with how her own nature is terrifying to mortals. She was met with the idea that she's some cruel thing. She was hated just as strongly as she was loved. And Death can't understand why she's unwanted. Death can't understand what is wrong with her. Death keeps balance, she keeps order. But for her scar, she bended the rules and gave her time. Death grants time. But it's never enough.
Rio needed to be accepted. Agatha was always going to be in denial. How could they balance the grief of losing a child, when Agatha wouldn't even acceot it being gone? How could they be anything but doomed, when their love created life so brief and fleeting? How could they ever be over each other, when even inside Wanda's Hex, Agatha's feelings for Rio were ever-present and she would always see her there?
When the words of Agatha's mother—you were born evil—were confirmed by the mere fact she could only take, and take, and take. And the only one she could give anything to, was Death? To keep her close, first, and then to keep her away, too busy to take her son? Because Agatha couldn't heal, or protect, or divine—she could only drain. And so Death was her satellite.
2) Alice Wu Gulliver & Billy Kaplan / Maximoff (“A lot happened to me at 13, too.” || “She was protecting you, but you don't deserve it.”)
The youngest ones, sharing the same aesthetics, whose lives were both cut short (in billy's case, cut in half) just as they were getting started. Haunted by scarlet and orange, even as their finger-tips are blue. A lot changed for each of them at thirteen—and all of it had to do with their mothers.
Each of then carries their own sort of curse. Alice's is generational—she's on the road to lift it. She's on the road to save herself. (Even if, at the end, she saves someone else at her own expense—which is her real curse, if you ask me.)
Billy has a sigil to lift, but even when it's lifted, he's not sure who he is. Is he William Kaplan, or is he Billy Maximoff?
Alice goes her whole entire life searching to find herself—but she never can. She's a shadow. Her mother's shadow–as is Billy. Each of them try desperately to make sense of the ashes left behind by their mothers. Each of them try to piece things together to understand what's wrong with them.
And each of them holds bitterness towards their mother. Alice claims that Lorna wasn't well. She feels that everything her mother taught her was a lie. She feels like her mother chose strangers—her fans, her coven, over her. Billy says that Wands isn't his mother at all, because he had a mom already. He doesn't remember her loving him. He only remembers her 'choosing a town full of strangers over her own flesh and wires.'
And as it happens, Billy and Alice both have no idea of the sacrifice and pain their mothers went through, all for their sake. The lengths each of them went to just to keep them alive, to protect them.
And Alice finds out. And her anger is replaced by sadness—sadness for her mom. But also catharsis—because what is grief, if not love persevering? Billy has yet to reach that point.
But when they understand each other so well, when they've bonded so strongly, from the very first trial—when they're the only ones who volunteer to dig Sharon a grave, who are sensitive to loss... Is it such a surprise that Alice's death is such a turning point for him? That his trust in Agatha wavers? That his power moves uncontrollably? It is not, because Alice is much like himself.
3) Lilia & Jen (“I'm not going before you.” || “You are the path ahead, Jennifer.”)
Jen and Lilia are juxtapositioned from their very first interaction. They immediately butt heads. And their relationship's development is crucial to each of their own developments.
From the moment each of them are introduced, they are parallels. First of all, they are frauds. They use some sort of lie that somewhat resembles their magical skillset, (Madame Calderu's Psychic Readings / Kale Kare) but actually requires no magic at all. They could be doing something important, but they've both found themselves unable or unwilling to. They're both hermits who have completely distanced themselves from the Witchcraft community, claiming that they don't need it, that they don't care for it. Their powers are both repressed—Lilia's because she choise to repress them, Jen's because they were forcibly bound. They both pretend they are content—toughened through the passage of time and the cruelty of history tiwards women like them—but they're both met by dead ends. Lilia's eviction notice, no different than Jen's upcoming lawsuits.
And they continue to butt heads throughout, judging each other. From 'chemical peel' to 'pitchy' & 'flat,' to Jen pushing Lilia out of the way because her own survival is her only priority. To then singing together, sharing scar stories, exchanging brooms, 'Jennifer, look what you did.' To opening up. To Jen no longer wishing to go before her, no longer wishing to put herself first. Because she sees her, now, as something more than a crazy old broad. She cares to see her—like no-one has in centuries.
And for Lilia, whose timeline, whose path isn't linear, Jen has always been there. Her family. Her sister in the craft. Whose presence she lacked, like a memory she couldn't grasp. Nostalgia she couldn't quite place anywhere. Nostalgia for something you've never even had. Because in the future, she always had her. And the flow of time is an illusion.
Lilia's road, her path, has always been windy. But Jen is her path ahead. The Path Ahead is in Lilia's reading. Jen is Lilia's path ahead. Not only because she has a brilliant and bright future of her own ahead of her in the mcu, now with her powers unbound. Because Lilia senses all the trapped light and bound power that Jen carries—(“The High Priestess: Immense spiritual power, unable or unwilling to use it--”) but also because Jen, the survivor, is the one who will carry on Lilia's memory. All those centuries, Lilia had been alone—there was no 'path ahead.' Everything was a jumbled mess. Her “path” was non-linear and twisty.
And Jen, after centuries of solitude, was her light in the dark, guiding her through the dark tunnels, as her mind wandered through her timeline searching for answers. Jen was the only person in centuries who bothered to see her as something more, to acknowledge her strength, and to help her fill in the gaps as best as she could. And so Lilia sees so much hope in Jennifer—who won't stop becoming better and better. Because Jen finally decided to put someone else first, to prioritise someone other than himself. To re-discover inside of her the nurturing, protective nature she had buried and bound alongside her magic. Because even when bound, she is a healing presence. She is still the midwife, the 11th generation root-worker. The woman who was doing something important—and she didn't need magic to be that woman.
Because for Jen, the Queen of Cups is her path behind. Wound suffered, lessons learned. “I couldn't save Lilia, I didn't even try to save Alice, I'll be damned if I let you two idiots die.” Lilia reminded her how to be a good person. And for Lilia, she was a light in the dark. Even as her path winds out of time—Lilia lives on in Jen. The one and only survivor of the Witch's Road—(since Billy is more of a Dungeon Master.)
And of course, a million other things can be said about each individual dynamic in this coven—because all of them were fated to meet, and all of them were written for each other. There is not a single unexplored dynamic in this group, not one. I could make a million other posts about each of them. Agatha & Billy -> motherhood. Agatha & Jen -> oppression and begrudging trust. Agatha & Alice/Lilia -> protection from a mother's love. The list goes on and on and on.