Marvel’s Secret Wars is one of the biggest comics events ever, but one which was initially intended to focus even more on Doctor Doom - a choice which may yet make it into the MCU, given the actual cause of the event's central disaster would be unlikely to satisfy movie audiences.
Secret Wars (2015) by Jonathan Hickman and Esad Ribic serves as not only the finale to Hickman’s Avengers runs, but also to his tenure on the Fantastic Four and even to the Marvel Universe as a whole. In the event, reality is destroyed by the cosmic horrors that are the Beyonders, with pieces of the multiverse only preserved thanks to the efforts of Doctor Doom. Doom then rules as a tyrant god over a 'Battleworld' constructed of multiversal fragments until stopped by the efforts of the few heroes to survive reality’s collapse. The MCU is heading for an adaptation of the story in 2026's Avengers: Secret Wars.
In an oral history of the event published by SKTCHD, Marvel editor Tom Brevoort and Jonathan Hickman discuss the original conception of the event, revealing that rather than the Beyonders, Secret Wars' central multiversal disaster - in which different realities crash together in an awe-inspiring cascade - was originally brought about by Doctor Doom. In FF #16, Hickman and artists Nick Dragotta and Steve Epting set up Doctor Doom in his own hidden universe, planning to build a new empire in the devastated base of the Council of Reeds. The Fantastic Four later confronted Doom, taking away his control of this reality. It turns out the conflict in this realm was going to kickstart the multiversal collapse. Brevoort states:
Almost nobody knows this, but the last issue of his Fantastic Four run would have been the inciting incident to Secret Wars had it not happened in Avengers. ... That story was all about (how) Doom had been knocked into a universe, and he took over the universe. Reed and Nathaniel ended up there and they have a conflict with him, and by the end, that universe is destroyed. And theoretically, had things progressed from there, that would have been the inciting incident that began the Incursions happening.
Doctor Doom Originally Started Secret Wars
Given that Doctor Doom is the ultimate villain of Secret Wars, it makes perfect sense for him to be part of the disaster that begins it. Indeed, while the comics do a good job of selling the Beyonders' awe and scope as the creatures destroying the multiverse, their motivations are so alien that it's easily the least satisfying aspect of the well-received event - ultimately, the heroes can't understand why the Beyonders are destroying the multiverse, other than that they're done with it. Making Secret Wars a tale of Doom's hubris from the very start makes him even more satisfying as the main villain - something which is likely to be especially true in the movies, where the mysterious non-reveal of the Beyonders' motivations would be less likely to satisfy, since it would lack the decades of comics setting them up as an inscrutable cosmic threat.
Secret Wars was an ambitious and impactful event that's still well-regarded by fans and critics, so it would be inaccurate to say that using the Beyonders rather than Doctor Doom was a mistake. It is however fascinating to know how the story was originally supposed to go, and to see how the ideas that began in Fantastic Four evolved as time passed. UItimately, the MCU will make changes big and small to the plot of Secret Wars, however the original idea of Doctor Doom causing the multiverse to collapse thanks to his hubris would work well on the big screen, where it would even be possible to make him one of Kang the Conqueror's many variants across infinite timelines, tying it to 2025's Avengers: The Kang Dynasty while still being its own narrative.
Source: SKTCHD