Steve Rogers aka Captain America is one of Marvel Comics’ most skilled fighters and is the valiant leader of the Avengers, but he possesses another power that evidently is a perk of his superhuman strength. Captain America can secretly depower every other super soldier that was created using the same methods that made him superhuman.
In What If…? #103 by Bill Rosemann and Dan Fraga, Captain America is awakened after being frozen in a block of ice since the ‘40s, and the world he wakes up to is very different from the Marvel Universe fans are used to. In this altered timeline, the scientist responsible for turning Steve Rogers into Captain America, Dr. Erskine, was never assassinated and went on to produce plenty more doses of the super-soldier serum. The future that came of that deviation in the timeline threw the world into a futuristic Sci-Fi nightmare.
In the future Captain America was suddenly thrust into, the Roxxon Corporation gained control over Erskine’s super-soldier serum and mass-produced it, offering it up to anyone who could afford it. To ensure people would continue buying their product, Roxxon tweaked the formula and made the serum addictive. The future became ridden with superhuman junkies while those who denied the serum were gathered into ghettos and looked down upon as a lower class. Once Captain America found out about this grim new reality, he knew he had to be the one to fix it. Sure enough, it was in his blood to do so, literally. Dr. Erskine discovered that the elements within Captain America’s bloodstream because of his exposure to one of the first doses of super-soldier serum held the key to depowering anyone else who took the serum. Without wasting any time, Cap and Erskine did what they needed to do to create the antidote that would rid people of their superhuman strength along with their complete dependency on Roxxon’s product.
Even though this event happened in a What If…? storyline, Captain America’s super-soldier depowering ability is still canon within the main Marvel canon. What If…? are a series of stories that depict what would happen if something in the main timeline went differently, meaning each story takes place on an alternate version of Earth-616 and not another Earth number across Marvel’s multiverse. Based on this logic, Captain America’s super-soldier depowering capability is canon, and if he needed to he could refine his blood into an antidote and take away the strength of anyone dosed with super-soldier serum.
Up until this point, it was no secret that Captain America could defeat basically any super-soldier he came up against as shown when he bested the Winter Soldier upon their initial encounters. With this What If…? storyline, fans learn that Captain America has another over other super-soldiers beyond his strength and skillful fighting abilities. Captain America can secretly depower every other super soldier by refining his own blood into an antidote that will take away their strength instantly.