From Red Skull to Red Hulk, Captain America has fought a plethora of villains in his various movies and shows in the Marvel Cinematic Universe

Anthony Mackie, Harrison Ford, Danny Ramirez and more lead the cast of Marvel's newest movie, 'Captain America: Brave New World.'

Brave New World raises a major question about the MCU: which superheroes are even left to help Sam Wilson defend Earth?

Brave New World brings adamantium into the fold. The substance shows up in the body of the Celestial that emerged from the Indian Ocean in Eternals. Now, it's the cause of international conflict, as major world powers try to control the world's only known adamantium supply.

Brave New World might not be the movie you'd expect to deal with a cosmic plot thread from Eternals, but it does ... sort of.

The previous Captain America feature, Civil War, released about 9 years ago. That was the last narrative where Thunderbolt Ross had a substantial role in a Marvel Cinematic Universe plot, and his Sokovia Accords are mentioned in Brave New World’s dialogue.