Even though Steve Rogers's story in the Marvel Cinematic Universe is over, the MCU in 2020 will be about evil Captain Americas. Avengers: Endgame may have given a poignant ending to the Star-Spangled Avenger's adventures, but the MCU isn't done exploring the impact and influence of Captain America. In fact, The Falcon and the Winter Soldier and Black Widow will involve different, evil versions of Captain America in 2020.
As fans saw in Captain America: The First Avenger, Steve Rogers (Chris Evans) became enhanced by the Super Soldier Serum, turning him into the greatest soldier in American history. Steve was frozen in ice in the waning days of World War II and was resurrected right before the Avengers assembled in 2012. Since then, he's been the leader of Earth's Mightiest Heroes, but he's also been a fugitive from the law; Rogers' refusal to sign the Sokovia Accords in Captain America: Civil War made him a wanted international criminal to the point where Peter Parker's gym teacher assumed Captain America was a "war criminal". But Cap's pure heart and desire to do the right thing has always rung true and this, not the Super Soldier Serum, is what truly made Steve Rogers both a hero and a good man.
Even though the original Captain America is out of the picture, and while Steve passed his Vibranium shield Sam Wilson (Anthony Mackie), his specter continues to loom large over the MCU. Here's how the Disney+ series and Black Widow are toying with evil versions of Cap and the varying ways that would impact the MCU.
John Walker AKA US Agent In Falcon And The Winter Soldier
Bucky Barnes AKA the Winter Soldier (Sebastian Stan) could already be considered the evil Russian equivalent of Captain America, but The Falcon And The Winter Soldier looks to introduce another anti-Cap equivalent: Wyatt Russell will play John Walker in the Disney+ series. In Marvel Comics, John Walker was originally introduced as Super-Patriot; he later took over the Captain America role from Steve Rogers before going on to become the U.S. Agent. While Walker had similar abilities to Captain America, he was the opposite in personality and temperament - a stark contrast to the noble Steve Rogers.
It's unclear if Walker will take on any of his comic book personae in the series, but since the U.S. Government is already uneasy about Sam Wilson inheriting Captain America's shield, plus he pals around with a former Russian assassin, The Falcon And The Winter Soldier's version of John Walker could provide a third and even darker version of Captain America, giving three different POVs on the meaning of Steve Rogers' heroic legacy.
Red Guardian In Black Widow
Naturally, Russia craved their own version of Captain America and he will be introduced in Black Widow: David Harbour (Stranger Things) is playing Alexei Shostakov aka Red Guardian. In the comics, Red Guardian doesn't have superpowers but he's a highly-trained hand-to-hand combatant - likely a graduate of the Red Room along with Natasha Romanoff (Scarlett Johansson) and Yelena Belova (Florence Pugh). Red Guardian also carries a shield similar to Captain America so he'll be a different spin on the Star-Spangled Avenger. Further, Red Guardian's mysterious connection to Black Widow could shed light on why Natasha Romanoff found it so easy to grow close to Steve Rogers when they were Avengers together.
Bonus: Zombie Captain America In Marvel's What If?
Although What If...? doesn't release in 2020, it will feature an evil Captain America when it does debut. What If...? will portray twisted scenarios drawn from the 23 MCU movies, and one of them will involve a zombie Captain America fighting the Winter Soldier. Marvel Zombies is something comic book fans have been clamoring the MCU to do and they got a taste in Spider-Man: Far From Home when Spidey (Tom Holland) had to face a zombified Iron Man in one of Mysterio's (Jake Gyllenhaal) illusions. Zombie Captain America is a straight-up horror take on one of the MCU's most beloved heroes, so it will be interesting (and likely very scary) to see an undead Steve Rogers portrayed as an outright monster.