Who is US Agent? Marvel's fake Captain America is a big Falcon and the Winter Soldier spoiler

Instead of the classical virtues of heroism and valor espoused by Steve Rogers as Captain America, imagine a more contemporary hero. One that reflects updated, edgier values. Enter US Agent.

An alternate version of the star-spangled superhero, US Agent is a Captain America rival from Marvel Comics who's about to enter into the Marvel Cinematic Universe. He made his debut on Sunday night during a very brief scene from Marvel Studios' "Big Game" spot during Super Bowl LIV. He's slated to appear in Falcon and the Winter Soldier, but is he friend or foe?

Here's what we can predict about the upcoming Disney+ show based on the character's history from Marvel Comics.

I blinked during the trailer. What did I miss?

Marvel aired its first Disney+ TV spot during the Super Bowl, and it features clips from WandaVision, Loki, and Falcon and the Winter Soldier. We see Sam Wilson practicing with the Captain America shield that an old Steve Rogers bequeathed to him at the end of Avengers: Endgame. We see Bucky Barnes (aka Winter Soldier) threaten Baron Zemo with a gun. At about the 20-second mark, we also see a man wearing what looks like a Captain America outfit run out onto a football field to high five the leader of a marching band.

He's only pictured from behind — prompting plenty of "America's ass" jokes online — so it's tough to tell exactly who we're looking at. However, specific set leaks from November indicate this is some kind of propaganda event at a large high school football game, and it's for US Agent (aka John Walker, played by Wyatt Russell).

So who exactly is US Agent?

We can't know for sure what role this person will play in the upcoming series, but a Marvel.com blog post previously confirmed "the addition of Wyatt Russell who will be playing John Walker, a character that most comic book fans will recognize."

In the comics, John Walker underwent the Power Broker process conducted by Dr. Karl Malus, the same guy who gave Jessica Jones and Trish Walker powers in Netflix's Jessica Jones series. As a result, Walker gains superhuman strength that surpasses even Captain America's. He uses that power to become a different star-spangled hero who's hardcore and totally okay with killing bad guys and using swear words.

John Walker isn't referred to in any official capacity as "US Agent," and that's because he has a long and storied personal history in the comics. After undergoing the aforementioned procedure, he becomes Super-Patriot and begins a public smear campaign against Steve Rogers' Captain America, condemning Cap's antiquated values in favor of a more modern approach.

In the comics, Red Skull manipulated the masses into turning against Steve Rogers, who stepped down from the role. This allowed Walker to become the new Captain America, but he was eventually stripped of the title for his extreme actions and assumed the moniker US Agent instead. Thankfully, he went on to become something of an anti-hero, working with the good guys on many different occasions.

He's just kind of a jerk.

What will US Agent do in Falcon and the Winter Soldier?

Marvel probably refers to John Walker by his real name and not as US Agent. That's because he won't actually be US Agent — at least in the beginning. Despite the fact that Steve Rogers gave Sam Wilson the Captain America shield and mantle, it appears that the US government has something else in mind, presenting Walker as its official replacement for Captain America.

The purposefully vague official description for Falcon and the Winter Soldier definitely makes this seem possible:

Following the events of Avengers: Endgame, Sam Wilson/Falcon (Anthony Mackie) and Bucky Barnes/Winter Soldier (Sebastian Stan) team up in a global adventure that tests their abilities—and their patience—in Marvel Studios’ The Falcon and The Winter Soldier. The series also welcomes the return of Emily VanCamp as Sharon Carter and Daniel Brühl as the villain, Zemo, plus the addition of Wyatt Russell who will be playing John Walker, a character that most comic book fans will recognize.

A test of their abilities, "and their patience," seems telling. Sam and Bucky could probably handle most direct conflicts with ease using their gadgets, guns, and, in Bucky's case, superpowers. But given their track record with Zemo's penchant for manipulating people into doing his bidding and the emerging conflict over Captain America's mantle, it seems pretty obvious that it's all connected.

The going assumption is that the government puts forth Walker as the new Captain America (and maybe even gives him superpowers), but through Baron Zemo's manipulations, Walker becomes compromised, forcing Bucky and Sam to save the day — and forcing Sam to define what it'll mean for him to be the real Captain America moving forward. Walker could even emerge at the end of the series as an unlikely ally for the rest of Marvel's Phase Four and beyond, but we'll know more as we get closer to the release of Falcon and the Winter Soldier.

Ok, now can I see that trailer again?

Yup. Here you go.

Falcon and the Winter Soldier debuts on Disney+ in Fall 2020.