Doctor Doom’s introduction to the MCU might feel rushed, but the multiversal war he’ll wage is years in the making. Since Thanos turned to dust the MCU has introduced new concepts, characters, and plot point that will play big parts in Avengers: Doomsday and its sequel Secret Wars. But which ones matter the most? These are the eight you need to know before Doomsday, either because they’re definitely important or because we think they could end up being more significant than you expect.
Sacred Timeline, Nexus Events, and the Tree of Life
Loki‘s first season introduced the concept of the Sacred Timeline to the MCU. He Who Remains (played by He Who Marvel Wants You To Forget About) had emerged victorious over his fellow Kang variants in a multiversal war fought between parallel worlds. That conflict had threatened all of existence. To prevent the cycle from happening again he merged all dimensions that only led to his existence—and not his variants—into a single shared Sacred Timeline. All universes existed on top of one another in a single repeating loop.
He Who Remains then created the Time Variance Authority (TVA) to deal with special variants who caused any unauthorized branches, new timelines that threatened the stability of the singular shared Sacred Timeline. Those branches resulted from Nexus Events.
He Who Remains wanted Loki and Sylvie to take over for him because he was tired, but in the show’s second and final season Loki took on a different job. He did not take over as the head of the TVA for He Who Remains. When Loki realized he could not fix the broken Temporal Loom that had bound the Sacred Timeline together he instead replaced the Loom and the Sacred Timeline with himself.
Loki burdened himself with glorious purpose by grabbing all of the timelines of existence and weaving them into himself as he claimed the throne as the King of All Time, Always. Only, unlike his predecessor who pruned entire universes, Loki did not oppress or eliminate any of them. Instead of a Sacred Timeline everyone existed as part of Yggdrasil, the sacred Norse Tree of Life.
Loki’s sacrifice, sitting alone at the end of time for all time, gave existence freedom. But all but guaranteed another multiversal war would happen. The TVA remained in operation to deal with He Who Remains’ variants, but Loki also made it possible for someone as dangerous as Victor von Doom to wage war against the multiverse. And there is reason for someone to do exactly that.
Incursions
Doctor Strange and the Multiverse of Madness introduced the concept of incursions to the MCU. An incursion is when the border/boundary between two parallel worlds is weakened or destroyed. They then crash into one another, annihilating either one or both timelines, killing trillions. Doctor Strange learned how his own variants had caused incursions across the multiverse. Traveling to other dimensions, including via dreamwalking, seems to be at least one cause of incursions. So long as anyone can travel across the multiverse any timeline is at risk.
Clea and Strange
Doctor Strange of Earth-616 (the primary MCU universe, according to the MCU and not Marvel Comics) helped saved America Chavez from Wanda Maximoff. Chavez is a singular being without any variants who has the ability to traverse the multiverse. But Strange’s efforts caused an unseen incursion, which he agreed to help stop when Clea arrived at the end of Multiverse of Madness.
Charlize Theron’s cosmic hero made a big impression during her only MCU scene. We saw her cut through the boundary between Earth-616 and the Dark Dimension. Her and Strange obviously make a powerful incursion fighting duo. But Clea’s partner is also extremely dangerous.
Doctor Strange’s Third Eye
Doctor Strange used the Darkhold to dreamwalk and save America Chavez, but in doing so he opened his evil third eye. One of his variants, known as Sinister Strange, had also sported a third eye on his forehead after studying the Darkhold, the evil book that had corrupted Wanda.
Sinister Strange caused an incursion that destroyed his timeline. Earth-616’s Doctor Strange, who we last saw traveling the multiverse to save a girl he didn’t know, couldn’t seem any different from his sinister counterpart. But that version of the superhero might be long gone by the time the sorcerer finally reemerges in Avengers: Doomsday. The Darkhold clearly left a lasting imprint on him. Between that and his efforts fighting incursions he could be a willing ally of Victor von Doom stated goal to keep the multiverse “safe.”
Strange’s home dimension of Earth-616 might have bigger issues, though.
Anchor Beings
Deadpool & Wolverine worked because it didn’t care about canon and continuity all that much, but the film still introduced a major new concept to the MCU: anchor beings. Wade Wilson’s universe was destined to die after the death of Wolverine in Logan. Rogue TVA agent Paradox explained why this happens. He said an anchor being is “an entity of such vital importance that when they die their whole world slowly withers out of existence.”
Tony Stark might have been Earth-616’s anchor being. That doesn’t just mean it could implode. That means it might be a risk to every dimension. In Marvel Comics the destruction of one world can cause a cascading effect on other worlds, a type of slow moving mass incursion event that threatens the entire multiverse. (The very thing He Who Remains was trying to prevent with the Sacred Timeline.)
Considering a Tony Stark variant is going to wage war on all other timelines, the idea of an anchor being could anchor the entire premise of Avengers: Doomsday.
Franklin Richards
Doctor Doom’s first and only MCU scene so far came during an end-credits scene in The Fantastic Four: First Step. Sue Storm found Doom in her home playing with her son Franklin, one of the most powerful beings in the entire MCU. Franklin has the Power Cosmic. The MCU has yet to fully explore what that means, but audiences got a sense of it from Galactus’ desire to use the boy as a replacement and when Franklin used his abilities to revive his dead mother.
Doctor Doom did not randomly stop by to say hello to his old friends’ kid. He knows Franklin is capable of incredible things that can reshape reality and all of existence.
Monica Rambeau
Marvel might not think The Marvels is important enough to rewatch before Avengers: Doomsday, but we do. The film was the first to introduce a world where the X-Men exist. When Monica Rambeau closed a pathway between Earth-616 and another dimension to prevent what we know would have been an incursion, she got stuck inside another dimension where Dr. Hank McCoy lives. Is that the same Beast from Earth-10005, the Fox era X-Men dimension that will appear in Avengers: Doomsday? We don’t actually know. But we know Doctor Doom won’t be happy with Monica or anyone else living in a timeline where they don’t belong. That’s how whole universes get destroyed.
Thor’s Daughter Love
We know this final entry might seem like an odd one to include, but Avengers: Doomsday trailer make us think it could prove vital. In the movie’s promos Doctor Doom tells his enemies they have all lived “stolen lives.” He’s not wrong, as the Avengers of Earth-616 and the X-Men of Earth-10005 both used time travel to cheat death. The trailer also include a big showdown between Thor and Doom and the God of Thunder talking about how he has never feared an enemy as much as he does his newest foe. Doom’s armor even includes a symbol of Thor.
All of that is especially ominous for Thor’s daughter Love, who truly lives a “stolen” life. She was long dead when her father Gorr reached Eternity and wished for her resurrection. Doom could target her, both because she shouldn’t be alive and because he wants to antagonize Thor.
Her death could be the impetus for Thor’s involvement in the multiversal war. It’s a battle the MCU has prepared for long before Doom was set to wage it.