“The truth is… I am Doctor Doom.”

Your Tony Stark may vary

It would be easy to dismiss the casting of Robert Downey Jr in Marvel’s upcoming Phase VI movies as a publicity gimmick, but that would be to underestimate the creative nous of the Russo brothers. Here's how I think they'll do it, given that the Russos know it would be pointless and disappointing to bring in Downey as an entirely different guy. Just as they know that a villain called "Victor Von Doom" who wears medieval armour under a green cloak is too dumbly comic-booky to play in the modern MCU. So it's obvious: in the Fantastic Four’s timeline, Downey will be playing… Tony Stark.

As in the regular timeline, Tony is injured by one of his own weapons -- and maybe also disfigured, though I suspect they'll drop that aspect of Dr Doom's origin as audiences will want to see him with the mask off. But things are different in this timeline. Maybe Pepper is with him in Afghanistan and gets killed. Maybe there's no Yinsen to point him on a better path. Maybe (oh, please) Raza is on course to becoming the real Mandarin and having him as a shadow-self only makes Tony more bitter and self-righteous.

Of course, in this timeline Tony has to be an old college buddy of Reed Richards at MIT, but after the death of his parents Tony went off to be a rapacious capitalist weapons dealer while Reed stuck with their youthful utopian ideals. As a brilliant but ruthless arms manufacturer Tony has dozens of nicknames on social media, one of which might well be "Doctor Doom". After he builds the suit (and note that the original suit design isn't far off the Kirby Doom's armour) he leans right into that soubriquet. Even so, through most of the movie I'll bet they'll be just "Tony" and "Reed" -- after all, there's not much that can be done with the name "Mister Fantastic" either except through the lens of irony.

And this will make for a much better character basis to the conflict. An old friendship gone sour, an antagonist who believes he's doing the right thing, regret at the path not taken, the faint possibility of redemption -- that will give a real spark to their dialogue together, and give us a chance to see Reed's fundamental decency contrasted with an arrogance we always half-knew only needed a nudge to go bad.

Or maybe I'm wrong and Anthony & Joseph Russo will come up with an even better way to work Robert Downey Jr logically into the Phase VI storyline. They've done some top-class work in the past, so I'm betting whatever they come up with will be worth the wait.