Loki may have opened the Multiverse, and Spider-Man: No Way Home may have showcased the early consequences of doing so, but it's Doctor Strange in the Multiverse of Madness that looks to be busting the door to the world of variants and alternate timelines wide open. This movie is about to change the MCU forever, and after his appearance in No Way Home, Doctor Strange is the perfect character to lead it.
The Tom Hiddleston-led series is said to be one of the projects that has prompted Marvel Studios to add lots of cameos to Multiverse of Madness, so it would be fitting for characters from the series itself to show up. It's worth noting that it has been reported that Hiddleston himself will appear in the series, and rumors that Sophia Di Martino and Owen Wilson will as well have also been floating around.
Doctor Strange 2 has already been confirmed to feature the debut of Marvel Comics characters such as America Chavez and the return of others such as the Scarlet Witch. However, given that Marvel's Multiverse is all about the variants of characters fans already love, there will surely be some present as well, like what appears to be an evil version of Doctor Strange himself as seen in the recently released teaser for the movie.
Loki was the project that first introduced the concept of Variants to the MCU, along with the Time Variance Authority. Although the TVA has been altered thanks to the convergence of so many timelines in the show's Season 1 finale, TemPads still appear to exist as methods of time travel, and it looks like they might just show up again in Multiverse of Madness.
Loki TemPad in Doctor Strange and the Multiverse of Madness?
One Marvel fan who watched the Doctor Strange in the Multiverse of Madness trailer spotted what they believed to be a Time Door akin to the ones which were opened by TemPads in Loki.
They pointed out the rectangle-like shape behind Wanda at about 40 seconds into the trailer glowed a similar orange color to the Time Doors seen in Loki.
Could Loki Characters Show Up in the Doctor Strange Sequel?
While it must be emphasized that this is just a theory for now, the orange glow emitting from what appears to be a vertical rectangular shape behind Wanda is an interesting coincidence. The Time Variance Authority is quite different at the end of Loki's first season compared to its beginning, but its methods of time travel appear to be the same. TemPads will likely continue to be used in Season 2, so why not in other MCU projects as well?
If the Doctor Strange and the Multiverse of Madness teaser DOES show a shot of a Time Door, the question is who could be using it. The shot makes it appear to be Wanda, as she is the only character in the frame, but it's possible another character could be using the door to step out behind her.
While it could just be a TVA hunter going after Wanda, there are a couple of plausible characters from Loki that could step through that sort of door and into the chaos the Doctor Strange sequel will bring. At the end of Episode 6, Sylvie is all along in the Citadel, having just killed He Who Remains and subsequently realizing his warnings of the Multiverse were correct. It is unknown where her story will go next, but she may just go anywhere she can to get out of there....and end up in the same place as the Scarlet Witch herself.
Mobius is another character who may very well show up, though it will depend on whether the alternate TVA seen in the Loki finale is a different TVA entirely or just a "reset" version of the one seen in the rest of the series. If it's the former, he could be trying to deal with the chaos which ensued at the end of the show and wind up in the presence of Wanda and/or other Multiverse of Madness characters.
It's unlikely that Loki himself will appear, however, given that his show's second season is said to pick up right where the first left off, and a Multiversal adventure in between would take Loki away from the moment in the new TVA he found himself in at the end of the finale. Given the number of Variants we'll likely see in Multiverse of Madness, though, it wouldn't be surprising at all to see one or two of the God of Mischief show up.
Doctor Strange in the Multiverse of Madness is set for a May 6 theatrical release.