Warning: This article contains spoilers for Agatha All Along episode 3, “Through Many Miles of Tricks and Trials”

Thanos has been heavily rumored to be returning to the MCU, and the real villain of Agatha All Along could explain exactly why the Mad Titan comes back. So far, Marvel Television’s Agatha All Along has raised more questions than answers, with episode 3, “Through Many Miles of Tricks and Trials,” only making things even more confusing. According to one popular theory, the real villain of Agatha All Along is yet to present themself fully, but they have already been seen, and they may have the potential to change the shape of the MCU forever.

Agatha All Along’s premiere, “Seekest Thou the Road,” not only reintroduced Kathryn Hahn’s Agatha Harkness, but also unearthed an age-old rivalry between Agatha and Aubrey Plaza’s mysterious Rio Vidal. Though she is said to be a Green Witch, Rio Vidal’s true identity has been the subject of some discussion. One popular theory suggests that Aubrey Plaza may have debuted as the darkest character in the MCU’s history, and one with an odd connection to Thanos, creating the opportunity for some intense and emotional scenes in Agatha All Along’s upcoming episodes and beyond.

Rio Vidal Is Lady Death? Agatha All Along Theory Explained

Lady Death Is A Very Powerful Being In Marvel Comics

Perhaps the most popular theory surrounding the true identity of Aubrey Plaza’s Agatha All Along character is that she is the MCU’s depiction of Lady Death. Lady Death, sometimes referred to as Mistress Death or simply Death, first appeared in Marvel Comics in 1973’s Captain Marvel #26, and she has always been depicted as one of the most powerful and formidable characters in the Marvel Universe. As the direct opposite of Eternity, who debuted in 2022’s Thor: Love and Thunder, it would be great to see Lady Death in the MCU.

Aubrey Plaza’s Rio Vidal has also been speculated to be Mephisto, Mephisto’s child, Blackheart, or simply just a Green Witch who may have a dark past with Agatha Harkness.

There have been many hints that Rio Vidal could actually be Lady Death in Agatha All Along’s first three episodes. Most notably, Vidal states that her heart is black in Agatha All Along’s first episode, and she suggests that Agatha Harkness had been hiding from her, perhaps by stealing the life force from other witches. Lady Death seemed to make an appearance in Lilia Calderu’s hallucination in Agatha All Along episode 3, and Death is even featured in the lyrics of “The Ballad of the Witches’ Road,” but there is one tease that is even more convincing.

Agatha All Along’s Tarot Cards Support This Wild Rio Vidal Theory

Tarot Cards, Including Death, Were Used To Promote Agatha All Along

Prior to the premiere of Agatha All Along, Marvel Studios spotlighted a selection of tarot cards, each with connections to the core cast of Agatha All Along, who come together to form Agatha Harkness’ new coven. These cards included the Three of Swords, the Queen of Cups, the Tower, the Three of Pentacles, the High Priestess and Death. While some refer to the grief of separation felt by Agatha Harkness and Alice Wu-Gulliver, the teamwork of the entire coven, the precognition of Lilia Calderu, or the spirituality of Jennifer Kale, Death is perhaps the most eye-catching figure.

Death is depicted as a hooded figure on the tarot card, and Rio Vidal makes her entrance into Agatha Harkness’ home sporting a fashionable hooded costume in Agatha All Along episode 1. She has also been seen in various other hoods in promotional footage for the series, but it’s her weapon that bears the strongest resemblance to Death. Death and Rio Vidal’s knives are exactly the same shape, with a recognizable curve in the middle. This is an overt hint that Aubrey Plaza is indeed playing Lady Death in Agatha All Along.

Aubrey Plaza Would Be Perfect To Play Lady Death In The MCU

Aubrey Plaza Has Always Gravitated Towards Dark & Mysterious Characters

Ever since she gained widespread recognition for her portrayal of April Ludgate-Dwyer in Parks and Recreation, Aubrey Plaza has become well-known for gravitating towards the weirder, darker and more mysterious characters. Lady Death fits this brief perfectly, as she is captivating, charismatic, sexy and dangerous, allowing Aubrey Plaza to give her MCU characters many complexities and layers. This bears resemblance to her previous Marvel character, Lenny Busker, a.k.a. the Shadow King, in Legion.

Having written, produced and starred in black comedies and experimental thrillers, such as Ingrid Goes West, The Little Hours and Black Bear, to name a few, Aubrey Plaza is a perfect match for the twisted character of Lady Death. Plaza worked alongside Scarlet Witch actor Elizabeth Olsen on the former, and her chemistry with Kathryn Hahn, given their past in Parks and Recreation, is palpable. Plaza is a huge asset to the MCU, so she deserves a role as pivotal as Lady Death, especially since this means she could appear in many upcoming projects, and alongside some surprising characters.

Lady Death’s Debut Would Support Thanos Returning To The MCU

Thanos Becomes Obsessed With Lady Death In Marvel Comics

While Marvel Studios may have made Lady Death something of a love interest for Agatha Harkness, it’s actually Thanos who regularly pines over the cosmic entity in Marvel Comics. Thanos’ obsession with Death started when he was an adolescent, as he became interested in nihilism and entropy. His love for Death would eventually lead him to collect the six Infinity Gems and wipe out half the population of the universe. Since Agatha All Along may have introduced Lady Death to the MCU, now may be the perfect time for Thanos to return.

In
Avengers: Infinity War
, Thanos collected the Infinity Stones to wipe out half the universe’s population due to his worries about overpopulation and resource management, not to court Lady Death.

Josh Brolin revealed back in February that Thanos may soon be returning to the MCU (via Comicbook). While there hasn’t yet been any sign of this happening, if Rio Vidal is revealed to be Lady Death in Agatha All Along, Marvel Studios could easily establish a connection between her and Thanos, bringing the Mad Titan back. Lady Death also forms bonds with Deadpool, Loki and Spider-Man in Marvel Comics, so there will be plenty of opportunity for Aubrey Plaza to reprise this exciting role after Agatha All Along​​​​​​​.

New episodes of Agatha All Along release every Wednesday at 6pm PT/9pm ET on Disney+.

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