At one point, Hermione quotes Shylock's famous speech to reassure Harry that he's still essentially the same person, and still her friend. Then it turns out that she's the daughter of Wanda Maximoff and granddaughter of Magneto, which by some customs makes her Jewish. "I am a Jew," indeed!
In this story, Black Widow and Hawkeye aren't a couple because their jobs are too dangerous. In the movies? He's got a wife and kids and names the latest after her (and as it turns out, said wife is also an ex-SHIELD agent, albeit retired)!
In the fancast the author made, he put Benedict Cumberbatch as Doctor Sinister. Several months later, Benedict Cumberbatch was cast as Doctor Strange, who in this fic views Sinister as his Arch-Enemy.
During the first book's Final Battle, Thor casually shows that he can still throw around lightning even without his hammer. Then along comes Thor: Ragnarok, and he has to go through a whole movie and an epiphany before he can figure out how to do that.
The first book's final battle also features Hulk smashing Chthon the same way he did to Loki, with the latter commenting on how gratifying it is to see it happen to someone else. Then Ragnarok comes along, and Hulk does that to Thor, with Loki being ecstatic about it.
Yet another from the same film is Thor's statement to Strange that "So Earth has... wizards now, huh?" Given that he used to be a wizard on Earth, that's definitely worth a chuckle from any viewer who's also a fan of this 'verse (as is Strange's penchant for screwing around with Thor and Loki, which one can easily imagine CoS! Strange doing as well).
Seeing how Steve briefly hooks up with Sharon Carter in the Marvel Cinematic Universe can be a bit awkward when you realize that she's his great-granddaughter in this fanfic.
When Harry and Carol first meet, they insist that they are Just Friends, and are set up to become Platonic Life-Partners with no Ship Tease whatsoever. One book and a case of Platonic Writing, Romantic Reading later (the author having apparently just shrugged and decided to go with it), they're still insisting that they're Just Friends, but literally no one, in-universe or out, is buying it. Lo and behold, they eventually get together in chapter 46 of Ghosts.
Occasionally in The Wizard in the Shadows, the author would break a chapter into two in order to avoid it becoming too "monstrously long." Come this fic, especially Ghosts, practically every chapter is at least half again as long as any in The Wizard In The Shadows. Whether or not this is a good thing is up for debate.
At one point during Jane's Bifrost experiments, Darcy was accidentally warped to another dimension and ended up bonding with Death of the Endless. Darcy's actress would later play Death in the series' audiobook adaptation.
The two Dresden Files books released in 2020 both have moments where Harry Dresden decides that he ought to imitate Doctor Strange. That gets pretty funny given that his character in this story is, following Wanda, Strange's eventual heir as Sorcerer Supreme!
In 2021, it was revealed in the 'Enter the Phoenix' arc of Jason Aaron's Avengers that Thor was the son of Odin and a Significant Green-Eyed Redhead Phoenix Host - a human mutant, no less. Much like Harry, Thor's son in this fic. Even the later reveal that she was technically more like his godmother, having 'rebirthed' him in Phoenix fire after he was born from Gaea and murdered by Laufey, only further drove the point home. Not for nothing has Nimbus occasionally griped that he should be on commission.
On the other hand, in this fic, Yelena Belova regards herself as better than Natasha, constantly insulting her and seeking to prove herself the "true" Black Widow. When the MCU introduced Yelena not long after, she turned out to greatly admire Natasha, to the point of Big Sister Worship! Nimbus has since observed that one of his bigger regrets is introducing this version of Yelena before the MCU version appeared, noting that it would have been very interesting to have her as a contrast.
The story's version of Doctor Strange has a strong affinity towards music, mixing it in with his use of magic on multiple occasions and emphasising how the two are connected in several of his lessons. Come Doctor Strange in the Multiverse of Madness the MCU Doctor Strange engages in a Wizard Duel with the combatants using music sheets as the focus and generating the corresponding notes.
In Book I, Fury shoots down Clint's mischievous suggestion that he make Hal Jordan the next Green Lantern, on the grounds that Hal's a bit of a Bunny-Ears Lawyer. Come Book III, Hal is a Lantern on Sakaar with the equivalent of fifteen years experience, capable of controlling at least four fully charged rings.
