
Captain America: Brave New World reversed the decision to kill off one character in the final cut of the film. The fourth Captain America film, and the first led by Anthony Mackie's Sam Wilson, contained several links to one of the first-ever Marvel Studios films, The Incredible Hulk. When Captain America: Brave New World was eventually released in February, it came after a series of lengthy reshoots that changed many major plot points.
One of these plot points involved the fate of Samuel Sterns/The Leader, aka Tim Blake Nelson's scientist, who was reintroduced after his first appearance in The Incredible Hulk. After initially trying to help Bruce Banner in The Incredible Hulk, Sterns was responsible for creating the Abomination, before a drop of Hulk's gamma-infused blood in an open wound led to his enhanced intelligence and deformed skull, which he possesses in Captain America 4.
The original color script for Captain America: Brave New World, posted by illustrator Sam Michlap on LinkedIn, reveals several cut moments from the initial story of the Marvel Studios film. One beat included Sterns's death, which would have taken place at the White House.

This moment would have seemingly occurred after Thaddeus Ross' (Harrison Ford) transformation into the Red Hulk, which Sterns orchestrated to ruin Ross's reputation as President, as revenge for keeping him captive for decades. However, in the film's theatrical cut, Sterns survives the events of Captain America: Brave New World and is imprisoned on the Raft (with several other major Marvel characters). He is sighted in one of the post-credits scenes of the MCU film, where he warns Wilson of looming dangers from the Multiverse.

Several things were changed about Sterns throughout Captain America: Brave New World's production, including his prosthetic design, which shifted significantly from the Leader's design in the comics. But it seems that it wasn't just Sterns' physical appearance that was altered during the development phase, but his fate as well. Sparing Sterns opens up the character to be used in future Marvel Studios projects, hinting that the MCU may not be done with Nelson's character.
Captain America: Brave New World released in theaters on February 14, 2025, and is available to stream now on Disney+. The Marvel Studios film was directed by Julius Onah and starred Danny Ramirez, Carl Lumbly, and Giancarlo Esposito alongside Mackie, Nelson, and Ford.
Why Did Marvel Studios Save the Leader?

The move to reverse the decision to kill Samuel Sterns in the original Captain America 4 script suggests that Marvel Studios has further plans for the hyper-intelligent character.
Sterns is revealed to be one of the only characters on the MCU's main Earth-616 who is aware of the coming conflict in the Multiverse. The post-credit scene indicates that Sterns is aware of Incursions, which is likely to be the overarching threat that is explored in Avengers: Doomsday. When Sam Wilson learns of the threat against his Earth in Avengers: Doomsday, he will no doubt remember the warning Sterns gave him, which would not have happened if the Leader died in Captain America 4's original script as planned.
While he is a villain to Sam Wilson and the Avengers, the Leader may end up being an ally to the superhero team. His advanced intelligence could be needed to understand how to survive the Multiversal threats that are coming in Avengers: Doomsday and Avengers: Secret Wars. Should the Leader choose to help, this could open the door for a redemptive arc for the Marvel villain.