Some of the extra scenes featured in the Iron Man, and has since then brought many Marvel Comics characters to life on the big (and small) screen. But this has worked in the opposite direction too, since Marvel released a variety of comic books that are now considered canon to the MCU. Some of these were original stories, detailing the likes of the inner workings of SHIELD and the Eternals' history on Earth, but others featured extra scenes that helped to flesh out live-action MCU adventures.
Many only know the canon storyline of the live-action films and Disney+ TV shows in the MCU, but the tie-in comics revealed new information about established characters, and finer details referring to throwaway lines in many Marvel Studios projects. The tie-in comics provided Marvel Studios with the perfect opportunity to tell more complex stories that there simply wasn't time for in a feature-length film, particularly when these films featured the origins of characters or their day-to-day operations as superheroes. Some of the extra scenes that were included in the tie-in comics drastically change how certain MCU moments are seen.
10 The Avengers Wasn’t The First Time Black Widow Had Met The Hulk
Fury's Big Week was released as a prequel to The Incredible Hulk before meeting the future Avenger in Kolkata, which was previously thought to be their first interaction, and adding more weight to the pair's eventual will-they-won't-they relationship.
9 The Leader Was Taken In By SHIELD After The Incredible Hulk
In the same run of Fury's Big Week, Black Widow witnesses the Hulk's battle with Abomination in Harlem during Captain America: New World Order.
8 General Ross Was Behind Justin Hammer’s Iron Man Attempts
Set after Iron Man but before Armor Wars.
7 HYDRA Had Arc Reactor Technology In WWII
Captain America: First Vengeance was set during the events of What If...?, which saw an alternate reality's Steve Rogers operate as the HYDRA Stomper.
6 The Ten Rings Are The MCU’s Longest-Running Villains
In the live-action MCU, the Ten Rings were introduced all the way back in Iron Man, but weren't fully explored until 2021's James "Rhodey" Rhodes, a.k.a. War Machine, is caught up in Hong Kong battling the forces of the Ten Rings, explaining why he was unable to help in the Battle of New York, despite already functioning as a hero at the time.
5 Gamora & Nebula’s Rivalry Makes More Sense In The Tie-In Comics
2014's Guardians of the Galaxy Prelude explores Nebula and Gamora's backstory before the events of the MCU's Guardians of the Galaxy, detailing their adoptions by Thanos and their endless sibling rivalry. The tie-in comic reveals that Nebula's hatred for Gamora runs deeper than the live-action MCU suggested, since it was Gamora herself who severely injured Nebula during a training mission, leading to Nebula's cybernetic enhancements. The story also reveals that, when Nebula gets herself caught in a trap, Gamora follows Thanos' instructions not to help her sister, causing her to amputate her own arm, which better informs Nebula's hatred for Gamora and Thanos in the MCU.
4 Hank Pym Saw HYDRA’s Memory Wiping Technology
It's been known in the MCU that HYDRA has memory wiping technology since Bucky returned during Captain America: The Winter Soldier, but 2015's Ant-Man Prelude in Marvel Comics revealed that this tech was seen by the MCU's original Ant-Man, Hank Pym. On a mission for SHIELD to East Berlin, Pym infiltrates a group of Russian terrorists who have reverse-engineered HYDRA technology, including their memory suppression machine. Pym even sees the machine being used on a subject, though it doesn't seem to be a huge success. This run gives a clearer insight into the pain that Bucky experienced during his imprisonment within HYDRA.
3 Kaecilius’ Storyline Mirrors Doctor Strange More Than Anyone Realized
Mads Mikkelsen portrayed Kaecilius in the MCU's Doctor Strange Supreme in What If...? episode 4. It's revealed that Kaecilius turned to the Mystic Arts after tragically losing his son and wife, consumed with the desire to command time and bring them back to life. This makes his motivations in Doctor Strange far clearer, as he simply wanted to be with his lost loved ones once again.
2 Black Widow Was Looking For The Winter Soldier Before Captain America
Captain America: The Winter Soldier revealed that Black Widow and the Winter Soldier had a bit of a past, though not much was made of this information, since the focus was on Steve tracking down his old friend with Sam Wilson's help. However, the Black Widow Prelude details the events of the Ambush in Odessa, the mission which brought Natasha Romanoff face-to-face with the Winter Soldier, causing her to get a gunshot wound to the abdomen. The Black Widow Prelude reveals that Romanoff tried to track down the Winter Soldier in the MCU, years before she would meet Steve Rogers and learn of his true identity.
1 The Avengers Could Have Reformed After Civil War
One of the most tragic storylines featured in the comics is that of the now-separated Avengers thinking about reforming after the events of events of Avengers: Infinity War, and the MCU as a whole, would've been wildly different.
