Did changes to the plot of the highest-grossing movie of all time, stealing Avatar's crown.
For all that's the case, though, the MCU isn't perfect. Marvel has been heavily criticized for its so-called "villain problem," with the bad guys typically underdeveloped because the focus has been on the heroes. Indeed, a common trope has been to use villains who are essentially twisted mirror-images of the heroes; think Obadiah Stane for Iron Man, Abomination for Hulk, and Red Skull for Captain America. This has the side-effect of meaning any character development for the bad guys actually serves to shine a light on the heroes' virtues.
It's true the MCU has improved in recent years; Vulture and Mysterio are stand-outs, and Avengers: Infinity War developed Thanos through an inverted heroes' journey. But, curiously, Marvel themselves seemed to believe an earlier villain would buck the trend; Kaecilius, the dark sorcerer of Doctor Strange. Sadly, this didn't prove to be the case, and it may well be because their plans changed.
Kaecilius & His Zealots Originally Seem To Have Been All About Death
Kaeculius' backstory is told in a prelude comic, The Zealot, published on ComiXology in 2016 and written by Will Corona Pilgrim. This is one of the best tie-ins, and it presents Kaecilius as a complex, conflicted character in his own right. He's shown as a man who has never recovered from the deaths of his wife and unborn child. Kaecilius jumped at the opportunity to find meaning in serving as a member of the Masters of the Mystic Arts, but in truth, his real hope was that magic would allow him to find a way to resurrect those he had loved and lost.
The prelude comic hints Kaecilius was being manipulated by another force, a powerful being who was casting spectral visions into his mind and guiding him along a dark path. In contrast with the movie, though, The Zealot seems to suggest his actions are orchestrated by the avatar of Death. In the comics, Death is a cosmic force who can manifest in visions and even corporeal form; although she serves the universal balance, she nevertheless has a hunger to consume life, and frequently chooses servants and pawns. Death is famous as the lover of Thanos, and Marvel certainly seems to have expected her to turn up in the MCU ahead of Avengers: Infinity War; she's The Avengers even has him form a huge smile when he's told battling humanity is "to court death."
Interestingly, concept art for the Zealots seems to confirm they were originally tied to Death as well. In one piece of concept art, they are shown dressed in sweeping black robes with white skull masks, looking rather like the Grim Reaper. Another piece of Doctor Strange concept art envisioned their bodies shattered between two dimensions, and they look almost identical to Death's Legion of the Doomed from Marvel Comics Presents #108. All this adds up to the possibility Death was planned as the main villain, the one who had orchestrated Kaecilius' downfall, and that Strange was supposed to prevent Earth being swallowed up by the Realm of Death - not the Dark Dimension.
Why Didn't This Death Arc Happen?
Putting the pieces together, then, there is some evidence Marvel Studios originally planned to use Death as the main villain of Doctor Strange. Those plans presumably changed in 2015, when Christopher Markus and Stephen McFeely began work on the scripts for Avengers: Infinity War and what would become Avengers: Endgame. Markus and McFeely seem to have made an early decision to deviate from the comics when it came to Thanos' motives; they removed the infatuation with Death, and instead presented him as a man who thought he was serving life by preventing a mass extinction event. Death was no longer necessary to Phase 3 of the MCU, and indeed would be superfluous, because her introduction in Doctor Strange would naturally lead viewers to expect a comic-book-accurate Thanos. Thus, when Doctor Strange began shooting in November 2015, Death would logically have been removed from the script and replaced by the Dread Dormammu.
If this is correct, Marvel Comics missed the memo. Behind-the-scenes tension had been building at Marvel for quite some time, with Marvel's reclusive chairman Ike Perlmutter locked in a bitter feud with Kevin Feige over his handling of the MCU. As a result, in September 2015 Disney forced a major corporate restructure, taking Marvel Studios out of Marvel Entertainment and placing Feige in charge. The relationship between the two Disney subsidiaries initially seems to have been quite strained, which is perfectly understandable given the unpleasant circumstances. That would certainly explain why the publishing arm wasn't told about the change in plans.
Death Would Have Been Better For Doctor Strange 2... But Not For Infinity War
The sad truth is that Death would have been a better villain for Doctor Strange than Dormammu. Kaecilius' backstory would be far more compelling as a pawn of Death; he would have been a tragic character, whose grief and sorrow had left open to manipulation by a ruthless being. Meanwhile, in thematic , Doctor Strange - a man who had fought death all his life, on the operating table - would have become the one whose sorcery defeats Death itself. Strange's progression would have been far more logical.
But this is the problem with a shared cinematic universe; everything is connected to everything else. Ultimately, Marvel made the right decision when they chose to rewrite Thanos' character; it allowed them to make the Mad Titan disturbingly sympathetic, because his motives - while still insane - were actually understandable. Far from lovestruck with Lady Death, he was someone who genuinely believed he was the hero of his own story. Thus Lady Death had to be cut - and the MCU as a whole is the better for it, even if Doctor Strange probably isn't.
