Even as the dust is settling from Spider-Man: Brand New Day and its mysterious ending and how it may lead to one or both of the Avengers sequels, all eyes are shifting to the next MCU movie to hit theaters, Avengers: Doomsday. Robert Downy Jr. is understandably drawing a lot of attention, thanks to his Marvel return as Dr. Doom. The actor is already showing off his method-dressing skills with a surprisingly dense Doom-themed wardrobe, and I think he may have divulged a major spoiler that possibly also ties back to Fantastic Four: First Steps. Let’s first dig into why I think RDJ unwittingly let the cat out of the bag regarding Doctor Doom’s second-in-command, and why I think it’s directly related to the final moments from the Fantastic Four’s MCU debut. Robert Downey Jr.'s Doctor Doom Shoes Feature A Coded Reference To Franklin Richards' SisterIf one scrolls through RDJ's post dedicated to his extensive Doctor Doom duds, one will come across a pic and video of some bright green shoes with the same rune-esque language that was emblazoned on the actor's jacket during his San Diego Comic-Con appearance. (That jacket is also included in the pic gallery, and its messages were previously figured out by Popverse.)A post shared by Robert Downey Jr. (@robertdowneyjr)A photo posted by on Using just the rune key first revealed in an Instagram post about Dom Latveria Coffee, I was able to figure out the word running across the strap above the laces:ValeriaFor those in the know, Valeria Richards is the name of two important characters related to Victor Von Doom. One is his former lover, with lots of demonic messiness attached to that storyline. More importantly for this line of theorizing, Valeria is also the name of Franklin Richards' sister, whose name was given to her by Doom, her godfather. Her exact origins changed over time, as comic origins are wont to do, but she is essentially an unborn child of Sue and Reed Richards' who gets saved and brought into existence through her brother Franklin's reality-altering powers. She possesses a genius intellect that leads her to invent advanced technology that allow her to travel through time, which can make her appear older than Franklin at times. Valeria also crafts an armor for herself that combines elements of the Fantastic Four's costuming with Doctor Doom's metallic protection. Which is what leads us to why I think this reveal is directly related to the ending of Fantastic Four: First Steps. Could Valeria Have Appeared To Franklin Instead Of Doctor Doom?SDCC was also the source of another big theory involving Doctor Doom, as the villain's hyper-detailed display statue was joined by a female counterpart of sorts identified only as "Latverian Witch." Fans quickly jumped to conclusions that the character could be Elizabeth Olsen's Scarlet Witch, or at least a variant of her, but the mask's smooth and sleek look seemed to be too close to the mask seen in Fantastic Four: First Steps' final moments, making me think it's the Witch who appears before Franklin, and not Doctor Doom as previously believed. I wasn't totally sold on Wanda Maximoff being under the hood in FF, but it would make a TON of sense for that to actually be Valeria instead. Even though it's been confirmed that Robert Downey Jr. filmed that scene, he's very clearly not holding the same mask he's wearing in the first Avengers: Doomsday trailer, so it stands to reason that it may not actually be the big bad. Valeria's comic book existence doesn't match up squarely with what the MCU has set up, so I would expect there to be unforeseen changes made that would match up with what the Russos have planned. But whichever way it goes, I'd fully expect her live-action debut to still feature the same close-knit relationship with Doom that makes everything complicated for the Richards fam. (Especially if she comes from a timeline where Sue and Victor are married. The horror!)Does this theory hold water, or does it sound like a wash? Robert Downey Jr.'s green shoes also feature lots of runes on the shoelaces and elsewhere that couldn't be fully seen, so perhaps those coded messages are all about former loves and are entirely specific to Victor Von Doom's ex. But I think it's more fun to believe that I unwittingly stumbled into a major Doomsday spoiler. We'll all find out for sure when Avengers: Doomsday hits theaters on December 18, 2026.