Aubrey Plaza's Agatha All Along mystery character is a cosmic Marvel entity with comic book connections to Thanos and Deadpool

Agatha All Along spent weeks dropping some seriously big hints about the secret identity of Aubrey Plaza's Rio Vidal - and many fans are now gratified to learn that our theories about her secret identity were right.

With Rio's true identity now confirmed, we'll have to discuss some Agatha All Along spoilers to get into it, so if you're trying to avoid all spoilers, turn back now.

As many people predicted, Rio Vidal is actually Death, as in the personification of death itself, a Marvel Comics character whose history is both strange and dire. Just like in the big reveal in Agatha All Along episode 7, in Marvel Comics, Death is often depicted as a partially skeletal woman - who has occasionally taken on human hosts to conduct her ghastly work on Earth.

The Death of Marvel Comics is a night-omnipotent cosmic being in addition to a constant of mortal life, who is depicted as the "sister" and opposite force of Eternity, who was adapted into the MCU as part of Thor: Ragnarok. 

What's more, just like the apparent ill-fated romance between Agatha Harkness and Rio Vidal, the history of Death in Marvel Comics is inextricably tied to one of Marvel's most devastating love stories - the often one-sided infatuation between Death and none other than Thanos, who, in comics, is romantically obsessed with Death herself.

In fact, in comics, Thanos' scheme to use the Infinity Gauntlet to eliminate half of all life in the universe is all a bid to win the attention of Death by sending untold trillions of souls to her doorstep.

Though their bizarre, on-again-off-again romance has continued over the years, with Thanos often courting Death, Death testing Thanos' loyalty in brutal and bloodthirsty ways, and both of them wreaking havoc in their wake, Thanos isn't Death's only paramour in the Marvel Universe.

Oddly enough, Death has also had strange romantic interactions with Deadpool, who is thought to be all but incapable of dying thanks to his healing factor. Still, it all comes back to Thanos, who made Deadpool's immortality official by cursing him to remain forever out of the reach of Death, just to keep them apart.

But Death later retired - apparently something cosmic beings can do in the Marvel Universe - imbuing a human named Marlo Chandler, who Death had previously possessed, with all her power as her replacement. Death took on the human form of Roberta Marshall, the deceased daughter of a woman who came face-to-face with Death trying to get her back.

Even though Death had the protection of the secret superhero team known as the Illuminati, Thanos found her and fought his way through all her protectors to absorb her essence into a new Infinity Stone - the Death Stone - seemingly leaving Marlo Chandler as the permanent new Death.

This brings us to Agatha All Along, which has been dropping hints, well, all along that Rio is Death. Way back in Agatha All Along episode 4, she literally climbs out of Sharon/Mrs. Hart's grave when summoned by the coven to fill the spot of their Green Witch, saying she was close by - seemingly claiming Mrs. Hart for the afterlife. 

Later, Agatha Harkness pleads with Rio when Teen is dying, asking her not to take him. She also states flat out that she plans to claim the souls of Agatha's coven, and she laughs in episode 5 when the Ouija board says "Death is nearby." And it seems to be implied that Rio is partially responsible for the fate of Agatha's lost son, Nicholas Scratch, who is apparently dead.

All of these clues were finally borne out in Agatha All Along episode 7, when Lilia's powers of precognition reveal Rio's true identity - though there are still plenty of questions to uncover about how Rio/Death fits into the cosmology of the MCU, and whether Rio herself might be one of Death's human avatars, as she often employs in Marvel Comics.

We'll find out more as the season finale of Agatha All Along premieres Wednesday on Disney Plus.

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