Everything you need to know before Avengers: Doomsday, including why Robert Downey Jr. is playing Doctor Doom, what happened to Kang the Conqueror, and how the Fantastic Four and the old X-Men fit in.

This is a calm, long-form explainer covering the background behind Avengers: Doomsday, currently scheduled for cinemas on 18 December 2026, the same date as a large sandworm picture some fans have nicknamed Dunesday. It walks through the comics history of Victor von Doom, the collapse of the Kang Dynasty plan after Jonathan Majors was dropped, the Hall H unmasking, and the five-hour chair livestream that became the biggest stream in Marvel Studios history. There is no countdown and no payoff at the end, so each section stands alone and you can drift off at any point.

What's covered in this video:

Who Victor von Doom is, from his first appearance in Fantastic Four issue five in 1962 by Jack Kirby and Stan Lee, to his origin in the fictional eastern European country of Latveria.
The university machine Doom built to contact his dead mother, the warning from his roommate Reed Richards, and the explosion that scarred his face.
Jack Kirby's stated design brief that Doom was meant to read as Death itself, modelled on the Man in the Iron Mask from the Alexandre Dumas novel, with armour as skeleton and hood as shroud.
Kirby's later claim that the scarring underneath is almost nothing, which reframes Doom as a perfectionist hiding from himself.
The Faustian bargain in Doom's family history, in which his mother Cynthia von Doom trades her soul to the demon lord Mephisto.
Why the casting was not a panic move, including reports that Kevin Feige held the Downey as Doom idea for years, and that Downey was in talks to play Doom in the mid 2000s Fox film before the role went to Julian McMahon.
The San Diego Comic-Con Hall H reveal in 2024, staged by the Russo brothers with a council of masked Dooms, and the "new mask, same task" line.
The 26 March 2025 livestream of 27 empty director's chairs, running five hours and twenty seven minutes, and reported figures of roughly 275 million digital views.
The names deliberately left off the chairs, including Tom Holland, Benedict Cumberbatch, Elizabeth Olsen, Mark Ruffalo, Brie Larson, Ryan Reynolds and Hugh Jackman, plus Ruffalo confirming Bruce Banner is not in the film.
The 2016 comic Infamous Iron Man, in which a healed Doom takes over the Iron Man mantle, as precedent for the mask tease.
The Kang plan built through Loki, He Who Remains and Ant-Man and the Wasp: Quantumania, and its collapse after the December 2023 verdict.
The writing handover from Jeff Loveness to Michael Waldron, the unused "first day as Kang" joke, and leaked, unverified details from the scrapped Kang Dynasty draft.

Mentioned in this video: Avengers: Doomsday, Robert Downey Jr., Doctor Doom, Victor von Doom, Marvel Studios, Kevin Feige, Iron Man, Tony Stark, Jack Kirby, Stan Lee, Fantastic Four, Latveria, Reed Richards, Mister Fantastic, Cynthia von Doom, Mephisto, Alexandre Dumas, Julian McMahon, Toby Kebbell, Fox, Anthony and Joe Russo, San Diego Comic-Con, Hall H, Jonathan Majors, Kang the Conqueror, He Who Remains, Loki, Ant-Man and the Wasp: Quantumania, Avengers: The Kang Dynasty, Jeff Loveness, Michael Waldron, Doctor Strange, Young Avengers, Ravonna, X-Men, Patrick Stewart, Professor X, Joseph Quinn, Human Torch, Vanessa Kirby, Sue Storm, Mark Ruffalo, Hulk, Bruce Banner, Tom Holland, Benedict Cumberbatch, Elizabeth Olsen, Scarlet Witch, Brie Larson, Ryan Reynolds, Deadpool, Hugh Jackman, Wolverine, Infamous Iron Man, Secret Wars, Dune, Twitter, Burbank

Chapters:
0:00 Why Iron Man Became Doom
3:32 Victor Von Doom Explained
7:22 Kirby Designed Doom As Death
11:35 Downey Almost Played Doom Twice
15:48 The Hall H Unmasking
19:29 The Five-Hour Chair Livestream
28:27 Kang Collapse Changed Everything
35:00 The Scrapped Kang Dynasty Leaks
40:03 Counting The Avengers Dead
51:39 Incursions And Loki's World Tree
1:02:50 Franklin Richards, Doom's Real Target
1:13:20 The X-Men Return Home
1:23:50 New Avengers And The Sentry
1:31:00 Filmed Without A Script
1:46:28 Secret Wars And God Emperor Doom
1:51:44 Dunesday, Records, And Backlash