Call Back / Doctor Strange in the Multiverse of Madness

• The teaser begins with echoes of lines from Spider-Man: No Way Home.
• Defender Strange says to America that in the grand calculus of the Multiverse, her sacrifice is worth more than her life, the same thing that 616-Strange said of the displaced villains in Spider-Man: No Way Home.
• Many to What If…?'s fourth episode "What If... Doctor Strange Lost His Heart Instead of His Hands?". The scene in the alternate Manhattan has reality slowly dissolving in a similar fashion to how it did in that episode. Similarly, Strange says that he "never meant for this to happen", nearly the exact words that his alternative self from the episode, Strange Supreme, said when he brought his universe's end on himself. Sinister Strange himself bears some similarities to Strange Supreme, but while Strange Supreme went down the wrong path for what he believed was a noble reason (albeit with blind disregard of the consequences), Sinister Strange has been corrupted by the Darkhold.
  • The episode also suggests that Christine and Stephen can never be together, and that trying to force the issue would break the universe. This movie reinforces that message by revealing that there is no universe in which they can get together. Another Strange Variant trying to force the issue also led to the destruction of his universe.
• Stephen turns Christine's glass of water into red wine, similar to the way he refills Thor's mug in Thor: Ragnarok.
• When the topic of Spider-Man is brought up, America, who doesn't know about the Wall-Crawler, asks Strange and Wong whether he can shoot web from his butt. Peter-1 asked a similar question to Peter-2 in Spider-Man: No Way Home.
• When Strange comes to recruit Wanda, she admits that she's done horrible things, alluding to her actions in WandaVision, only for Strange to confirm that he's not here to talk about Westview.
• The teaser poster features bars containing variants of Strange and Wanda. The first Dr. Strange film had one of Stephen's first spells (in Mordo's words "tampering with continuum probabilities") use this visual.
• When Strange hears that Earth-838 has a group called the Fantastic Four, he notes that said group was a band that "charted in the sixties," which nods to the encyclopedic knowledge of music history he displayed in his first film.
• Captain Carter says, "I can do this all day" while fighting 616-Wanda, just like Steve Rogers used to do in his films.
• Captain Carter is cut in half at the waist with her own shield by 616-Wanda, much like Zombie Captain America was by Bucky Barnes.
• The possessed, and undead, Defender Strange can be seen doing a variation of the multi-armed illusion that 616-Strange did to Thanos on Titan. Only this time, the arms are skeletal and black.
• 838-Wanda and her sons are living in a house that looks very similar to the one 616-Wanda created in WandaVision.
• Earth-838 Wanda is seen crushing the head of an Ultron Sentry, much like she did to the heart of Ultron in Avengers: Age of Ultron.
• In Doctor Strange, Stephen tried to use a cup-like relic against Kaecilius but did not know how to use it. Here, Christine uses this relic to fight off a group of damned souls attacking Stephen's body by holding a candle in the other hand which makes the cup unleash blasts of fire.
• As with Avengers: Infinity War, the titular conflict eventually came to the ruins of Titan on Earth-838 (and with that world's Strange also on that particular battlefield). The look of Earth-838's Titan and its Thanos also matches the looks of their Earth-616 counterparts).
• After drinking some tea tampered with by 838-Mordo to put Strange and America to sleep, America asks what was in it. Stephen asked a similar question after drinking with the Ancient One in his debut film.
  • When Baron Mordo argues against helping Doctor Strange find the Book of Vishanti, Charles Xavier responds by echoing the words his X-Men Film Series counterpart said to his past self in X-Men: Days of Future Past.
• In WandaVision, Wanda's Hex accidentally gave Monica Rambeau superpowers. In this movie, the Scarlet Witch shows that if she can give superpowers, logically she can take them away, which she does on Monica's own mother's 838 counterpart.
• Strange uses Dreamwalking to possess and reanimate the corpse of his counterpart, invoking another zombified Dr. Strange that appeared not too long.
• Wanda angrily calls Strange a hypocrite for dreamwalking, much like Kaecilius did the same towards the Ancient One for also using forbidden magic from the Dark Dimension.
• As in Agents of S.H.I.E.L.D., the Darkhold is shown explicitly corrupting the minds of all those who read it.
• Strange’s biggest regret: not being able to save a sibling’s life (in his case a sister) is similar to Marc Spector’s backstory (in his case, it was his brother).