Spoiler Alert

In a series full of scene-stealers, Aubrey Plaza’s witchy Rio Vidal character in Agatha All Along is up near the top. Yet we still don’t really know much about her. All we know is that she’s exceptionally powerful, and has a tangled past with Agatha Harkness which has led to a Kill Bill-style knock-down battle between the two in the first episode. Her name, or alias more likely, roughly translates to “River of Life.” There’s been a good amount of evidence that lets us know that Rio and Agatha clearly had a past romantic relationship, the details of which are a mystery.

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There’s also plenty of evidence to suggest that Rio Vidal is more than just a regular witch. When she shouts “I’m not a green witch, I’m THE Green Witch” in a demonic voice in episode four? That itself already tells us she’s more than meets the eye. But what if she’s actually Marvel Comics’ version of Death itself? Or the being known as Blackheart? Or perhaps, an amalgamation of the two? Here are the clues leading us to believe Rio is far more than she appears to be. And how what she may truly be has deep ties to Marvel Comics lore.

Who Is Mistress Death in the Marvel Comics?

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In the comics, Death, sometimes called Mistress Death or Lady Death, is a cosmic entity, older than creation itself. Created by Jim Starlin and Mike Friedrich, she first appeared in 1973’s Captain Marvel #26. As the name suggests, she’s the physical embodiment of death itself. Death is similar to other Marvel eternal entities like Eternity or the Living Tribunal. Both beings appeared fleetingly in recent MCU projects. Eternity popped up in Thor: Love and Thunder. And there was a “blink and ya miss it” cameo of the Living Tribunal in Multiverse of Madness. So it would be fitting for Death to also appear in the MCU in some form.

Thanos and Deadpool Both Love Death

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In the comics, Death usually appears in a skeletal form in a black hood. But she also occasionally looks like a Caucasian woman with black hair. The Mad Titan Thanos was obsessively in love with her. In The Infinity Gauntlet, his infamous snap erasing half of all life in the universe was done to impress her. But Death was never that impressed, and always rebuffed his advances. Simply put, she was above him.

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Years later, she admitted to “some” love for him. Eventually, the two combined energies to create a child, called the Rot. Death was left out of Infinity War and Endgame, and Thanos had new motivations for the snap in the MCU. We hope if Rio is indeed Death, she jokingly refers to Thanos’ obsession with her at some point. Ironically, in later years, a flirtation blossomed between Death and Deadpool of all people. As someone who can’t die, Deadpool might fall under the category of “wanting what you can never have.”

The Clues Spelling Out That Rio Vidal Is Death

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There have been visual cues aplenty that Rio is really Death from the start of Agatha All Along. She appears in a black hood when she attacks Agatha’s house in the first episode. She wears a similar hood on the Witches’ Road in episode four, although this one has a bit more ‘70s glam to it. Her distinct curved dagger is also held by the image of Death in Lilia Calderu’s Tarot deck. That can’t be a coincidence. All signs point to Rio Vidal somehow being Death itself.

Rio clearly loved Agatha at some point, and we feel their relationship will be explored in future episodes. Rio describes her “scar” as the pain she feels when she had to hurt someone she loved by just doing her job. Our guess is that as Death, it was Rio’s “job” to take the soul of Agatha’s son, Nicholas Scratch. Perhaps this was in exchange for the Darkhold? Whatever happened, Rio “just doing her job” put a black mark on their relationship. When privately talking with Agatha in the recording studio of Lorna Wu’s house, she implies heavily she’s there to take the souls of the other witches. Also, when Teen is near death, Agatha looks to Rio and says “Don’t.” The implication here is that Agatha (possibly believing Teen is somehow her son Nicholas) doesn’t want Death to come for him.

Rio Vidal May Also Be Blackheart

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Of course, Rio might be more than just Death from the comics. The MCU loves making amalgamations of characters. When Lilia gave Agatha her list of names for forming her coven, the fifth name that seemingly freaked out Agatha was an image of a black heart. In the comics, Blackheart is the “son” of Mephisto, created from the accumulated dark energy Mephisto gathered from a location known for its many murders. Blackheart became a primary adversary of the hero Ghost Rider. He originally resided in a Hell dimension, although Mephisto banished him to the Earthly plane.

When Rio appears, she crawls from the ground where Sharon Davis (“Mrs. Hart”) was buried after her untimely demise. She hints that she may have come from a realm beneath. Well, that realm could be Hell itself. Maybe Death needs some sort of corporeal form in the realm of the living. In the comics, she’s taken a human host before, when dealing with the Scarlet Spider. Her corporeal form may be that of Blackheart, a child of Mephisto. After all, we did get a Mephisto name drop at last in this series. There is probably a reason for that, beyond just establishing the character in the MCU. Death, Blackheart, a combo of the two, we imagine whoever this Rio Vidal/Green Witch truly is will reveal herself in the next few weeks.