Doomsday’s Secret Weapon Against Robert Downey Jr.’s Doctor Doom Has Already Debuted According To MCU Theory

Robert Downey Jr.’s Doctor Doom could be stopped by a recently-introduced Marvel Cinematic Universe character, as a new Avengers: Doomsday theory explores what could be the Avengers’ secret weapon against Victor von Doom. I’m not expecting Downey’s Doctor Doom to go down without a huge fight. After all, Josh Brolin’s Thanos completely changed the MCU in his Avengers movies.

I expect the same from the Multiverse Saga’s main villain in the upcoming Avengers movies. While we still do not know much about Avengers: Doomsday‘s story at this point, Downey’s Doctor Doom will go up against a few Marvel teams, which include Captain America’s Avengers, the New Avengers, the Fantastic Four, Fox’s original X-Men, and more. Doom should be extremely powerful.

That leads me to think that the Avengers will need an unorthodox way of going up against the villain. Much like how time travel needed to be involved in defeating Thanos in Avengers: Endgame, I believe that Avengers: Doomsday‘s cast of heroes will look for a secret weapon against Doctor Doom, and it could be a new Multiverse Saga character.

Mephisto’s MCU Debut Bound Him To A Hero

The Perfect Actor Has Been Cast As The Frightening New MCU Villain

Mephisto did not debut in WandaVision as had been rumored, but the villain made his MCU entrance four years later in Ironheart. The Disney+ series was much more interesting than I expected it to be, with some solid work where Mephisto and magic are concerned. The MCU villain is here to stay, and Sacha Baron Cohen’s Mephisto has already left his mark.

Mephisto raises his eyebrows with his head bowed in Ironheart

Mephisto’s Battle With One Of The MCU’s Most Powerful Characters Was Just Set Up

Mephisto has finally arrived in the MCU, and the new villain should fight one of the franchise’s most powerful characters after his debut set it up.

Initially, it came in the form of a deal with Parker Robbins that made him the Hood. Then, in Ironheart‘s final episode, Mephisto appeared to Dominique Thorne’s Riri Williams. Since Iron Man’s MCU replacement had already been on a dark path previously, which briefly made her a criminal, I was wary of how her meeting with Cohen’s Mephisto would go.

Actor	Role In Ironheart
Dominique Thorne	Riri Williams
Anthony Ramos	Parker Robbins/The Hood
Lyric Ross	Natalie Washington
Manny Montana	Cousin John
Alden Ehrenreich	Zeke Stane
Sacha Baron Cohen	Mephisto

It turns out I was right to be scared, as Riri Williams made a deal with Mephisto. In exchange for something she would not miss, a mysterious proposition, Riri’s best friend, Natalie, was resurrected. That ended the MCU series by bounding Riri to Mephisto, with mystic scars growing on her body. I believe that could impact Marvel Studios’ upcoming Avengers movies.

Mephisto And Doctor Doom Are Connected In The Comics In 1 Dark Way

Marvel Comics Presents How The MCU Could Link The Two Villains

Mephisto looming over Doctor Doom in Marvel Comics

Robert Downey Jr.’s Doctor Doom is confirmed to be the classic Victor von Doom version of the character. That means that if the MCU goes for a mostly comics-accurate approach with Doom, then he will have quite an interesting connection to Mephisto. The reason for that is how Mephisto has control over Doom’s mother, Cynthia von Doom, in Marvel Comics.

Mephisto was then able to torture her for eternity, which her son, Doctor Doom, was furious about.

Cynthia made a deal with Mephisto, which had her sign her soul away to the demon lord. Mephisto manipulated her into not only killing her enemies with the power he gave her, but also every child in the village. When she realized what she had done and gave up her power, soon being killed, Cynthia’s soul became trapped in hell with Mephisto.

Mephisto was then able to torture her for eternity, which her son, Doctor Doom, was furious about. Once every year, Doctor Doom was given the chance to fight Mephisto or his champion, always losing. The two Marvel villains have fought one another several times in the comics, and the MCU could adapt that in Avengers: Doomsday and/or Avengers: Secret Wars.

Avengers: Doomsday Theory – The Avengers Use Mephisto Against Doctor Doom

The Devil Should Have A Few Surprises Up His Sleeve

The fact that Ironheart premiered so close to Avengers: Doomsday is interesting. While that was not the initial plan for the show, Mephisto is still making his MCU debut right before the Avengers movie comes around. That means Marvel had enough time to prepare a possible role for him in the film while making sure the character became well-known ahead.

In the new Avengers: Doomsday theory, Mephisto is the secret weapon against Robert Downey Jr.’s Doctor Doom due to their comic book connection. If the heroes were to learn about Mephisto’s deal with Doom’s mother, then they could have some leverage over the villain, which they never did against Thanos, who even sacrificed his favorite daughter, Gamora, for his plan.

In Agatha All Along, there were rumors that Agatha Harkness’ son had become an agent of Mephisto. That could be what both the Hood and Riri Williams have become in Ironheart now that they have his mark. As Iron Man’s MCU replacement, it is interesting that Riri would become an agent of Mephisto right before RDJ’s return in Avengers: Doomsday.

That is yet another connection between two characters who share a lot of time together in the comics. Ironheart also dealt with the combination of magic and technology, which Doctor Doom is extremely famous for. As such, I believe the MCU is building up to Mephisto playing the Avengers in Doomsday, helping them against Doctor Doom but with an ulterior motive.

How Mephisto Could Impact Avengers: Doomsday In Another Way

There Are Always More Deals With The Devil To Be Made

There are other ways for Mephisto to be involved in Avengers: Doomsday without the devil having to control the soul of Doctor Doom’s mother. For instance, Mephisto made deals with multiple characters who appear in the Avengers movie in the comics, such as Loki and Sue Storm. After Ironheart, he could manipulate more MCU heroes in Avengers: Doomsday.

Mephisto (Sacha Baron Cohen) persuading in Ironheart Season 1 Ep 6

Mephisto’s MCU Debut Leads To The Scarlet Witch’s Resurrection In Marvel Theory

Marvel Studios’ latest TV show debuted one of the franchise’s biggest villains, and his arrival leads to the Scarlet Witch’s return in a major theory.

Those could even include resurrections, as he was revealed to be able to perform those when he brought back Natalie in the Ironheart finale. Many of the characters in Avengers: Doomsday have lost loved ones, so there are several ways this could go. It would even allow Downey to play Doctor Doom and Iron Man in Avengers: Doomsday.