Since the release of the Spider-Man: No Way Home trailer, fans have noticed that Doctor Strange is acting a little different from his usual self. The trailer shows Stephen and Peter working together to try and execute a spell that will allow them to erase Spider-Man’s true identity from the memory of everyone in the world, so that Peter can escape persecution from Mysterio’s false accusations.
Stephen Strange is usually pretty reserved with his magic, only ever casting major spells during times of crisis and catastrophe. He took on more of a backseat role during the Infinity Saga, primarily using his powers to go through the possibilities of how the Avengers could defeat Thanos. He then allowed himself to disappear after the snap and he never messed with the natural progression of the timeline for something as important as saving Tony Stark's life. It’s definitely out of character for Strange to wipe the memory of Peter Parker from the minds of millions, just because Peter asked him to.
A lot of fans have been speculating that it’s actually Mephisto posing as Doctor Strange, but there’s another MCU character who’s known for his use of magical illusions that could be impersonating the sorcerer. It’s everyone’s favorite God of Mischief, Loki.
According to a fan theory posted by Redditor Aggravating-Humor-88, Loki has more to gain by impersonating Stephen Strange. Loki has a motive to rip open the multiverse on Earth, because he blames himself for Sylvie killing Kang during the Loki season 1 finale. The theory suggests that Loki wants to find Sylvie to correct their mistake and the easiest way to do so is by posing as Strange to have access to the multiverse.
Loki has been known to transform into other people before, including his father during Thor: Ragnarok and even Captain America for a brief moment during Thor: The Dark World. The Loki series also revealed just how powerful Loki variants can be, and Hiddleston’s Loki knows that he still has a lot left to learn. Pretending to be Strange to have access to ancient magic would allow him to dabble in a new form of illusion.
Additionally, Marvel fans have already witnessed characters pretending to be someone they’re not during Spider-Man: Far From Home. During the post-credits scene, Nick Fury and Maria Hill let down their disguises and revealed themselves to actually be Skrulls. While that scene most likely alludes to some of the events that will unfold during Secret Invasion on Disney Plus, it could also have been foreshadowing to the secret identity behind Doctor Strange in Spider-Man 3.
Although the theory proposes the idea that this Loki/Strange character purposely designed the spell to cause multiversal chaos, another possible explanation for Strange’s decision to help Peter could be for the sake of keeping up appearances. If Loki was posing as Doctor Strange and Peter approached him asking for help, Peter would probably realize something was wrong if Loki/Strange didn’t lend a hand.
When Bruce Banner approached the Ancient One during Avengers: Endgame, she told him that Stephen Strange is meant to be the greatest sorcerer to ever live. Strange claims to be getting "distracted" by Peter talking, which is when the spell went awry. If the Doctor Strange fans saw in the trailer was truly himself, it’s unlikely that he would make such a massive mistake, which makes the entire situation a little fishy.
However, If it was actually Loki who was doing the spell then it would make a little more sense. Loki is still unfamiliar with his own powers, so mastering Strange’s sorcery would be an incredibly difficult task. Small disturbances, such as a teenager talking his ear off, could easily make spells go wrong for Loki.
The Reddit user later points out some other small details from the trailer that makes all signs point to Loki. Doctor Strange appears to be residing in a home that’s frozen over. Strange probably wouldn’t have any reason to live somewhere so cold, but Loki was born a frost giant. He could easily survive somewhere that’s freezing, and staying somewhere so cold would most likely offer Loki some sense of privacy as he tries to figure out the multiversal disaster caused by Sylvie. The Reddit user also noticed that Strange has his hair slicked back, which is a style that Loki has worn in the past, but Strange hasn’t.
Marvel is notorious for planting the smallest of details into their projects that often reference some sort of major reveal they have planned for the future. Although some fan theories can be far-fetched, it does seem plausible that Loki could be pretending to be Stephen Strange for his own personal gain. If Loki were to approach the heroes as himself, it’s likely that they wouldn’t want to help him, because he’s proven himself to be so untrustworthy in the past. By taking on another identity, Loki could start making progress towards fixing the multiverse, without receiving backlash from the TVA or other MCU heroes.