There are bound to be a number of magical superheroes in Doctor Strange in the Multiverse of Madness thanks to the movie's exploration of the multiverse. While many of them will be variants of known characters, there are many others just as powerful and iconic as Doctor Strange not only in Marvel Comics but from DC Comics as well.
Foremost among them is the Scarlet Witch, who will appear in the movie, and Agatha Harkness, who could potentially show up as well. In DC superhero comics, several powerful magical beings like Doctor Fate and Zatanna are coming to the big screen in the near future, opening the door for fans old and new to all kinds of magical and mystical heroes and worlds.
Brother Voodoo
Brother Voodoo is a powerful magical from the Marvel Universe and likely a character who will appear in the movie or in the very near future of the MCU. Brother Voodoo draws tremendous power and knowledge from the practice of voodoo, including summoning spirits.
He first appeared in Strange Tales #169 and was quickly associated with Doctor Strange and the larger world of magic in Marvel. Brother Voodoo actually took over as Sorcerer Supreme in Marvel Comics in the early 2000s for a time.
Constantine
John Constantine is one of the most powerful magical beings in DC Comics, and one of the most well-known thanks to his appearances in movies and on television. Though Constantine (also known as Hellblazer) possesses vast mystical knowledge, he rarely deploys it.
Even so, he demonstrates enormous power and skill in magic, in particular the ability to make or sustain his own luck. This has come in handy for him in the comics as he's generally the target of various and often powerful mystical threats.
Wiccan
Wiccan is able to manipulate and alter reality through mystical means, an extraordinary ability that he likely inherited from his mother, the Scarlet Witch. He's also able to generate lower-grade spells like generating energy blasts and force fields.
Wiccan is a member of the Young Avengers and has already appeared in the MCU, at least in the form of Billy Maximoff in WandaVision. It's likely another, older version of him will emerge in the MCU, perhaps as soon as Doctor Strange in the Multiverse of Madness.
The Spectre
The Spectre is one of the most powerful magical superheroes in the DC Universe. A major force in the DC realm since the Golden Age of Comics, he's basically a god, able to manipulate not just reality but time and space on a scale that's unimaginable.
He is immortal and essentially invulnerable, though not immune to other powerful magicians, as has been seen on a number of occasions in the comics, including The Blackest Night crossover event, where he faced off against Nekron.
Magik
Magik isn't only one of the most powerful X-Men from Marvel Comics, but also one of the most powerful magicians. Illyana Rasputin is the ruler of Limbo and wielder of the Soul Sword, able to enhance her magical power and diminish that of others.
Illyana is a mutant first and foremost, able to teleport between dimensions, which is how she wound up in Limbo in the first place. She has appeared in The New Mutants movie and will certainly the MCU at some point in the future.
Zatanna
Zatanna is an illusionist who actually happens to be one of the most powerful and important magical superheroes in the DC Universe. She's able to conjure an infinite number of spells and on top of that, she's also a powerful telepath and telekinetic.
Zatanna will be the focus of a solo movie in the DCEU, and as a member of the Justice League and Justice League Dark, she's certain to be a major force in the DCEU going forward.
Clea
Clea has long been a powerful sorceress in the Marvel Universe and now thanks to the recent death of Doctor Strange in the comics, she's one of the most powerful versions of the Sorcerer Supreme. Clea is the niece of Dormammu, the ruler of the Dark Dimension.
She's on par with Doctor Strange in power at this point in the comics, and able to amplify her own natural mystical abilities with the Flames of Regency, a powerful magical force that helped her defeat the Enchantress, a powerhouse sorceress herself.
Doctor Fate
Doctor Fate is one of the most powerful magical superheroes in DC Comics. He's somewhat similar to Moon Knight in that derives his mystical abilities from ancient Egyptian relics, in particular the Helmet of Fate, possessed of the spirit of Nabu.
Much like Doctor Strange, Doctor Fate is able to travel through dimensions and time, and it's likely he will do so when he appears in the DCEU's Black Adam movie. He's likely a conduit between the different branches of the multiverse in live-action.
Agatha Harkness
Agatha Harkness has become very well known to MCU fans in the last year as the villain in WandaVision. She's more complicated than that in the comics, as she's a mentor and friend to the Scarlet Witch. She's also closely associated with Fantastic Four, first appearing in issue #94 of the series.
Agatha Harkness is an ancient witch, present at the sinking of Atlantis, and capable of enough mystical power to cause the Scarlet Witch to forget her children ever existed. This led to terrible consequences for the entire Marvel Universe, in particular for mutants.
The Scarlet Witch
The Scarlet Witch's legacy as a hero in the comics is complicated, first appearing as a villain in Uncanny X-Men #4 and decimating mutants in House of M, but in recent comics and in the MCU she's one of the most powerful magical superheroes.
In fact, she is likely the most powerful. Wanda is a Nexus Being, a singular figure in the Marvel Universe capable of truly cosmic power. She's likely to display the same capabilities in the MCU, especially as she grows in power and knowledge.
