Avengers: Endgame Iron Man theory changes the MCU forever

Tony Stark died so everyone could live. That definition of "everyone" may extend to heroes we have not yet met in the Marvel Cinematic Universe — but heroes we're dying to meet all the same.

Get your vibranium-foil hats on, folks, because this Avengers: Endgame theory humbly submits some classic Marvel Comics heroes who have yet to make their MCU debut are already waiting in the wings. All thanks to Iron Man's sacrifice.

The Final Snap — Thanos wiped half the universal population away with the snap of his fingers. The Hulk rectified that mistake with a second snap. But a third snap was the final one: Tony Stark using the Infinity Stones to defeat the Mad Titan and his goons once and for all.

The gut-punching moment comes in the final act of Avengers: Endgame as Tony embraces what Dr. Strange envisioned as the one way forward for life to persist. Stark wields the stones, lets the cosmic power course through his veins, uses it to kill Thanos, and dies shortly after as a result.

What does Iron Man buy with his death, aside from one final quippy one-liner and the satisfaction of wiping Thanos' wrinkled face off the map forever? For many people, that's more than enough all on its own … but what if there's more to his move than meets the eye?

All in the Family — Tony Stark lives on even after his death in one crucial way: a powerful final monologue that's not only a celebration of the Marvel Cinematic Universe but a beautiful sign-off for the loved ones he leaves behind.

He says, in part:

"I'm hoping if you play this back, it's in celebration. I hope families are reunited, I hope we get it back and something like a normal version of the planet has been restored, if there ever was such a thing."

What's that, Tony? Something about family reunions? Funny you should say that since Marvel fans all the world over have their eye on one family in particular.

Marvel's First Family — This is obviously a wild theory, but let's play this out.

Imagine a world where Reed Richards, Sue Storm, Johnny Storm, and Ben Grimm are out in space on an expedition, before receiving the powers that turn them into the Fantastic Four. Thanos snaps half of all life out of existence. Reed, Sue, Johnny, and Ben are all part of that number.

Five years pass.

Hulk snaps his fingers, bringing back everyone who was snapped away. The Richards family returns, placed back safely in their ship, but it's now in very wrong hands. They are either forced to fight their way free from whatever alien planet has a hold of their ship, or they have to fly away from some cosmic entity — a Thanos loyalist, perhaps — that has also returned from the post-Snap life.

Enter: Iron Man, snapping Thanos and his allies out of existence. Depending on how he wielded his own snap, Stark's actions could impact the far-reaches of space, as far away as whatever conflict Reed, Sue, Johnny and Ben face — potentially instigating some sort of cosmic incident in the process.

The short version of this galaxy-brained theory? Iron Man's snap creates the Fantastic Four. (Or at the very least, saves them from death at the hands of some intergalactic Thanos henchmen.)

The Inverse Analysis — There are so many ways of pulling the Fantastic Four into the Marvel Cinematic Universe. They could already exist and we just haven't met them yet. Perhaps they are indeed already in some galaxy far away. Personally, I love the idea of Marvel's First Family living it up somewhere in the Quantum Realm, waiting to make their Marvel debut alongside Scott Lang and the Pym family.

But imagine a world where Tony Stark's final act not only defeats the MCU's deadliest enemy yet but also paves the way for a brand new superhero group's arrival. It adds powerful new meaning to Iron Man's death and connects the Fantastic Four to the other Marvel heroes in an even deeper way.

Is it likely that we'll meet the Fantastic Four thanks to Iron Man's sacrifice? No, it's not. It's a "galaxy-brained theory" for a reason. But it's a fun one to consider, that's for sure.

Avengers: Endgame is streaming now on Disney+.