The time heist sequence in Avengers: Endgame featured the Battle of New York in 2012, but having Bruce Banner pay a visit to the Sanctum Sanctorum actually created a major plot hole for the MCU’s continuity.
As a Master of the Mystic Arts, Stephen Strange maintains that the order has a duty to protect Earth from forces of darkness. Even in Thor: Ragnarok, the Sorcerer Supreme explains that he keeps a watchlist of individuals who “may be a threat to this world.” This, of course, included the God of Mischief. As such, Strange promptly trapped Thor’s brother in the void as soon as they arrived on Earth. But if such a solemn oath exists, why didn’t the Ancient One do more to stop Loki’s invasion in 2012?
In fairness, we wouldn’t have really thought of that if Endgame didn’t include a high stakes time travel plot. In fact, for all we knew, the Ancient One may have been preoccupied with some other incident at the time. Yet, the movie makes the crucial mistake of showing her in New York, defending their mystical hideout from the Chitauri.
Of course, the Sorcerer Supreme is a being of immense power. What we saw Strange do in Infinity War and Endgame, especially against the Mad Titan himself, is but a fraction of his extraordinary capabilities. So, why didn’t his predecessor do more to stop Loki?
As ScreenRant notes:
The Masters of the Mystic Arts led by the Ancient One in 2012 were tasked with protecting the Earth from mystical threats and this responsibility remained the same years later but with Doctor Strange now leading the charge. Loki fit the description of the sorcerers’ target beings perfectly; aside from his ability to use magic in varying ways, he was also in possession of two Infinity Stones: Mind and Space Stone. Since the Ancient One was the keeper of the Time Stone, she should’ve known how massively dangerous the villain was at that point in time. Given this, she and her subordinates should’ve been compelled to actively help in defeating the trickster and his Chitauri army, but instead, she decided to stay put and leave the newly-assembled Avengers to deal with the God of Mischief on their own.
The obvious answer here is that the MCU didn’t have plans for Doctor Strange just yet. And even if it did, including the order of sorcerers would just overwhelm the story. As long as we’re nitpicking, though, I think it’s safe to say that this is another one of Avengers: Endgame‘s inevitable plot holes that exists because of the time travel element.
