After Ironheart‘s shocking villain reveal, Spider-Man: Brand New Day may have received its most likely antagonist. Destin Daniel Cretton’s Spider-Man: Brand New Day is in active development and set to release in July 2026. As is natural for an MCU character as famous as Spider-Man, fan theories about the sequel’s plot, characters, and villains abound. From Scorpion to Mister Negative, many seem like ideal candidates for Spider-Man: Brand New Day‘s main antagonist role.
Ironheart was also the subject of several fan theories thanks to the Hood’s magical powers. Once Ironheart‘s second half released, the theories around Mephisto’s MCU introduction were proved correct. Marvel’s Mephisto has officially made his MCU debut, played by Sacha Baron Cohen, and he’s likely to appear in other upcoming MCU movies and shows. One of these projects could be none other than Spider-Man: Brand New Day.
Mephisto’s MCU Debut Makes One Spider-Man: Brand New Day Theory More Likely
Mephisto May Be The Reason Why Sadie Sink’s Marvel Character Arrives
As soon as Sadie Sink’s MCU casting was announced, fan theories around her character’s idenтιтy soared with possible heroes and villains. Jean Grey, Firestar, and an alternate-universe Mary Jane Watson seem to be some of the most popular choices. However, one particularly interesting candidate for Sadie Sink’s MCU role is Mayday Parker a.k.a. Spider-Girl, Peter Parker’s daughter from the future. In the comics, Mayday Parker is closely tied to Mephisto.
Sadie Sink’s Mayday Parker might come from the future or a different timeline to stop Mephisto from wreaking havoc on Earth-616
Why Mayday Parker would travel back in time or to a different universe is unknown, but Mephisto’s MCU debut in Ironheart would provide the best explanation. In the comics, Mephisto is deeply afraid of a prophecy that says Peter Parker and Mary Jane’s daughter is destined to defeat him. This is why Mephisto develops a special fixation on Spider-Man and fears the unborn Spider-Girl more than any other powerful hero or villain.
In the MCU, Sadie Sink’s Mayday Parker might come from the future or a different timeline to stop Mephisto from wreaking havoc on Earth-616. Since Spider-Man: Brand New Day is releasing close to Avengers: Doomsday, there might be some multiversal elements at play. This may also get Tobey Maguire and Andrew Garfield’s Spider-Men involved, or even imply that Sink’s Mayday is the daughter of either of the multiversal Spider-Men.
Spider-Man: No Way Home’s Ending Fits Mephisto & Mayday Parker’s Brand New Day Theory
Mayday Parker & Mephisto’s MCU Debut Might Connect Directly To Spider-Man’s No Way Home Spell
Rather than simply coming from another timeline to defeat Mephisto, Sadie Sink’s Mayday Parker might travel to Peter Parker’s timeline to convince Peter to reunite with MJ and thus allow Mayday to be born. At this point, Tom Holland’s Peter may be getting used to the idea of never reaching out to MJ and Ned Leeds again, but Mayday could arrive to help him change his mind. By ensuring she’s born, Mayday would be securing Mephisto’s defeat in the future.
Again, Sadie Sink’s Mayday doesn’t need to be the daughter of Tom Holland’s Peter and Zendaya’s MJ, as the MCU has established that closed time loops are uncommon. Instead, Peter’s emotional support to his two multiversal counterparts in Spider-Man: No Way Home may have convinced Maguire’s Peter to reinforce his love with Mary Jane and Garfield’s to find his MJ. One of their daughters, Sadie Sink’s Mayday, could travel through the multiverse to help her Earth-616 counterpart be born.
Avengers: Endgame references Back to the Future as an example of time travel rules that don’t align with the MCU’s. However, a very similar plot would be possible with a multiversal Mayday Parker.
Sadie Sink’s Mayday Parker may be inspired to help Holland’s Spider-Man after defeating her own version of Mephisto. After all, Mephisto is a multiversal villain in the comics, at least since he created his multiversal variant team, known as the Council of Red. In this theory, Sacha Baron Cohen’s Earth-616 Mephisto could survive, as the prophecy technically requires his own universe’s Mayday to fully destroy him. Defeated, the MCU’s Prime Mephisto could set his sights on ᴀssembling the Council of Red.
Mephisto’s Return In Spider-Man: Brand New Day Would Explain The Punisher’s Supporting Role
The Punisher May Be Tempted By Mephisto In Brand New Day
Besides Sadie Sink’s mystery character, Jon Bernthal’s return as Frank Castle a.k.a. the Punisher in Spider-Man: Brand New Day has raised a variety of fan theories. If Mephisto is Spider-Man: Brand New Day‘s main villain, then Bernthal’s Punisher might also get tangled in the demon’s plans. Mephisto could tempt Frank Castle to sign a deal that brings his family back, after which the Punisher could track down Mephisto as the demon tries to manipulate Spider-Man as well.
If Mephisto does convince Frank Castle to sell his soul in exchange for his loved ones, then the MCU could present a comic-accurate Cosmic Ghost Rider
Knowing the Punisher, Jon Bernthal’s Frank Castle would probably reject Mephisto’s proposal just like he rejected the offer to clean his record in The Punisher season 2 finale. Still, any ruse Mephisto comes up with could affect him, leading the Punisher to ʙuтт heads with Spider-Man. The Punisher made his first-ever comic book appearance in 1974’s The Amazing Spider-Man #129, where the Jackal put Frank Castle at odds with the webhead. Marvel Studios could replace the Jackal with Mephisto.
However, if Mephisto does convince Frank Castle to sell his soul in exchange for his loved ones, then the MCU could present a comic-accurate Cosmic Ghost Rider. In the comics, an alternate-universe variant of the Punisher signs a deal with Mephisto to host the Spirit of Vengeance and exact revenge on Thanos for annihilating his universe. This Cosmic Ghost Rider then travels to Earth-616 and joins the Guardians of the Galaxy.
Mephisto’s Villain Role In Spider-Man: Brand New Day Would Flip Peter Parker’s No Way Home Mistake
Spider-Man Could Turn His Past Mistakes Around To Defeat Mephisto
Tom Holland’s Peter Parker has been notoriously naive since his introduction in Captain America: Civil War. Peter attacked the Vulture’s crew completely unprepared in Spider-Man: Homecoming, gifted Mysterio the EDITH glᴀsses in Spider-Man: Far From Home, and pushed Doctor Strange to cast a botched spell in Spider-Man: No Way Home. Following the memory-wiping spell’s aftermath, Holland’s Spider-Man should now be more responsible.
Peter Parker must be wise enough to reject a wish-granting stranger who tempts him with the idea of undoing Spider-Man: No Way Home‘s ending. Mephisto might try various different ways to acquire Spider-Man’s soul, but Peter would do everything he can to protect it. Spider-Man: Brand New Day is the beginning of a new chapter for Tom Holland’s Spider-Man. As such, it needs to portray Peter Parker as an evolved hero in strength of character.
Spider-Man’s rejection of Mephisto’s offer would also flip the controversial comic that served as inspiration for Spider-Man: No Way Home. In Spider-Man: One More Day, Peter gives up his marriage with Mary Jane so the whole world forgets his secret idenтιтy. In Spider-Man: Brand New Day, Tom Holland’s Peter Parker could reject Mephisto’s temptations while trying to restore his relationship with MJ.