John Walker’s jealousy of Super Soldiers and interest in the serum in The Falcon and the Winter Soldier proves that he doesn’t understand who Steve Rogers (Chris Evans) really was or who Captain America is supposed to be. After getting frustrated at how easily Bucky stopped him and having convinced himself the only thing holding him back was not being a Super Soldier, in episode 4, Walker (Wyatt Russell) gave in to temptation and took the Power Broker’s serum.
In Marvel comics, Walker acquired super strength from the Power Broker and was later selected by the United States government to replace Steve Rogers as Captain America. The MCU went in a similar route by making Walker Steve’s successor in The Falcon and the Winter Soldier but offered a twist on his story. His MCU arc began with him lacking powers of any kind. Unlike Steve, Walker was just a skilled soldier - a highly decorated one, but still just human. That changed when Walker got a chance to inject himself with the Super Soldier Serum. Now, Walker possesses the enhanced physical capabilities of his comic book counterpart. With his new strength, however, came a lack of boundaries, and he publicly brutally killed one of Karli Morgenthau’s Flag-Smashers in front of a large crowd.
Not only does he lack the morality of the hero who once wielded the shield, but he also lacks a fundamental understanding of who Steve Rogers was as a person and what it means to carry the shield. It’s true that he originally had good intentions, and that if he had the serum, he’d be able to prevent more lives from being lost. The problem, though, is that physical superiority is all he saw in it. Walker’s reasons for taking the serum stemmed from the feeling of inadequacy that has plagued him since he picked up the Captain America shield. Walker failing to apprehend the Flag-Smashers and losing to the Dora Milaje all contributed to him feeling that he wasn’t good enough and that he needed to be physically stronger to be a good Captain America for the country.
That’s different from how Steve Rogers felt about it. He volunteered for the experiment because he wanted to make a difference in the war effort, not to become powerful. Dr. Erskine (Stanley Tucci) recognized the goodness in Steve and picked him despite the fact that he wasn’t the best choice physically. He could have picked someone who fit the mold of a “perfect soldier” but that’s not what he had in mind. He wanted his Super Soldier Serum to go not to that perfect soldier but to a good man. Based on what the show has revealed about John Walker, it’s easy to see that he wouldn’t have been on Dr. Erskine’s radar.
The serum bringing Walker's worst qualities to the surface and enhancing them was foreshadowed by Battlestar’s comments earlier in the episode. Battlestar pointed out that “power just makes a person more of themselves,” which echoes Dr. Erskine’s original explanation in Captain America: The First Avenger. He said that it “amplifies everything that is in inside,” explaining that “good becomes great; bad becomes worse.” That’s why it’s not all that surprising that Walker, who already showed signs of a troubled and aggressive temperament, went too far in the fight with Flag-Smashers. Walker’s approach to proving himself stems from a place of insecurity and may ultimately lead to his downfall in The Falcon and the Winter Soldier.
