Spider-Man’s multiversal variants are atomically unstable in Spider-Man: Into the Spider-Verse, but the two Spider-Man iterations in Spider-Man: No Way Home experience no such dangers, prompting the question of why. Sony’s critically-acclaimed animated film brought Spider-Man iterations from different realities to the big screen for the first time in 2018 before the MCU united all three live-action versions of the web-slinger together in No Way Home. The reason why the two films depict such different effects of multiversal travel has to do with what brought the different Spider-Man variants together.
Miles Morales, who was bitten by a similar genetically-altered spider as Peter Parker, takes on the mantle of Spider-Man after witnessing the tragic death of the original web-slinger following a battle with Kingpin, who attempts to tap into the multiverse with a Super Collider. The machine brings numerous Spider-Man variants to Morales’ home reality, and each suffers from a condition nicknamed “glitching,” in which their atoms are excruciatingly unstable. The variants will eventually die unless they return to their native realities, adding an additional conflict for Miles Morales' Spider-Man.
Related: Spider-Verse 2: How Did Gwen Get Back To Miles Morales' World?
No Way Home brings Tobey Maguire and Andrew Garfield’s Spider-Man iterations and several of their respective villains into the MCU, but none of the characters experience the same atomic ailment as the variants in Into the Spider-Verse. This is likely due to the Kingpin’s Super-Collider affecting Spider-Man variants differently from Doctor Strange’s multiverse-altering spell, with the magic of the latter providing a far smoother transition between realities for the
Read more on screenrant.com