Avengers: Doomsday arrives December 18, and the marketing machine is already at full roar: a giant Doom throne installation in Shanghai, a trailer teasing Latverian witches, and Marvel telling fans to “assemble respectfully” while sharing popcorn art of the villain. Let’s separate the confirmed from the conjectured.

Confirmed: Joe and Anthony Russo direct, from a Stephen McFeely script. Robert Downey Jr. plays Victor von Doom — not, per Anthony Russo’s own pointed wording, “simply some alternate Tony Stark wearing Doom’s armor,” but a fully committed Doom, built with a performance-capture digital layer and a distinct voice and accent. Downey wrote backstory and pitched costume ideas. The mask stays on.

The ensemble is the largest Marvel has ever assembled: Chris Evans as Steve Rogers, Chris Hemsworth’s Thor, Pedro Pascal and Vanessa Kirby as the Fantastic Four’s Reeds, Anthony Mackie’s Captain America, Florence Pugh’s Yelena, plus Tom Hiddleston, Benedict Cumberbatch, Sebastian Stan, Paul Rudd — and the X-Men cavalry: Patrick Stewart, Ian McKellen, James Marsden among them. The official logline: heroes from three distinct universes on a deadly collision course against an existential threat.

The release-date theater is its own show: December 18 puts Doomsday head-to-head with Dune: Part Three — “Dunesday,” per Downey himself. And the runway is deliberate: the Endgame: Encore re-release carried new footage tying directly into Doomsday, the five-episode Countdown podcast is walking fans through the saga, and a Brand New Day re-release with extra footage is reportedly being positioned as a bridge.