James Buchanan “Bucky" Barnes a.k.a the Winter Soldier, is one the most iconic villain-turned-hero characters in the Marvel Cinematic Universe. He is the best friend of Steve Rogers (Captain America: The First Avenger) and was considered killed in action during the battle with Hydra in World War II. After being reborn as the Winter Soldier, Barnes became a rival to the star-spangled hero because he shared many traits with him but also had some aspects that made him a wholly different, and altogether unique mirror to Steve Rogers. This made him a strange character to rival Captain America, but he's been the Cap himself in the comics, and he could even take on the role in the films. Here's why.
10 10. Better Enhanced Super Human Strength
After losing his arm in the line of duty, Barnes received an upgrade from his generous and hospitable captors, Hydra. Unlike Steve, Barnes did not undergo a super soldier serum infusion and was given basic steroids to promote muscle development and was then trained to achieve the peak physical condition the human anatomy could attain. The bionic arm he was given also allows his strength to grow exponentially and the force behind a punch from this arm was enough to force Steve Rogers to use both hands to defend against it.
9 9. More Experienced
Before becoming the Winter Soldier, Bucky Barnes was part of the military and served alongside Steve Rogers. During World War II, Bucky went on missions together with Captain America and, given his military training, was a very skilled advance scout.
However, after the war Steve spent seventy years in a comatose state encased in ice. Bucky, meanwhile, kept fighting - admittedly while brainwashed. This makes Bucky more prepared and battle ready, as he has had more time to prepare for different scenarios than Cap has.
8 8. Better Adaptability
Though both Rogers and Barnes have trained extensively in multiple types of martial arts and even became some of the world's best hand to hand combatants, Barnes still pulls a little bit ahead. Unlike Rogers, who has only used small 9mm secondary firearms such as a Glock 17, Bucky has trained using assault rifles, sniper rifles, handguns, and machine and sub-machine guns as well. This allows him to adapt to any situation faster and increase the firepower with the equipment he has either on his person or in his surroundings.
7 7. Bigger Arsenal
While Captain America may have the indestructible vibranium shield, the Winter Soldier also has some useful gizmos that complement his strengths. Barnes sports a new and improved vibranium cybernetic arm (courtesy of King T'Challa), which can project energy, discharge an EMP, project holographs and enhance his reaction time. He has an assault rifle for a zoning/ranged style combat, a combat knife for those silent assassinations and close quarter fighting, and a handful of grenades for more explosive approaches. He can also use Roger's vibranium shield with approximately the same style and consistency and he does this despite never taking any super soldier serum to begin with.
6 6. More Conventional
Though Rogers has had his fair share of battles and experience, Barnes outclasses him by miles. Steve is well versed in military tactics but that’s it. His time as an ice cube left him lacking in this department once he came into modern society.
Barnes however, spent his whole life as the Winter Soldier, training to be a master spy, assassin, and an expert of espionage. This makes him more malleable and adaptable, allowing easy kills, undetected surveillance, information extraction via enhanced reconnaissance and skilled sabotage. He is also fluent in over seven different languages including English, while Cap is still catching up on the world today.
5 5. Knows His Limits
Rogers is human, but after receiving the super soldier serum he becomes more daring. He understands that he can be killed very easily, but his enhanced physical and mental attributes allow him to perform some of the most daring and crazy stunts with less concern about the risks that follow them. Barnes, however, does not have the same physical boost as Steve (lacking his super-serum) and so, relies on his years of knowledge to come up with ways to add strengths and cover up his weaknesses. An example would be his shock-absorbing costume made up of a blend of Kevlar/Nomex to help absorb large shocks but not hinder his agility.
4 4. Knows Hydra Better
During his stay with Hydra, Barnes was subjected to excessive mental torture, where he was brainwashed to respond to every command once a sequence of code was orally narrated. The brainwashing also wiped out memories of his past life and when he showed signs of regaining his memory, he was rescheduled for a fresh brain drain. However, Barnes' subconscious was able to retain pieces of information during his out of body experience and after freeing himself from their custody and manipulation, he had all the necessary knowledge that was required to bring the organization down to its knees and even end it permanently should they rise fully again.
3 3. Willing To Cross The Line
Unlike the moral teachings that Captain America follows and the justice system he puts his faith in, Barnes is aware of the true nature of the world and will not hesitate to take a life. Over the years as Winter Soldier, Barnes was deployed on many assassination ops which made killing a second nature to him.
He tries to make amends for all the innocent blood he shed by going after the power hungry, corrupt politicians, and any person affiliated with Hydra, but unlike Steve, Barnes does not hesitate to pull the trigger for those who don’t deserve to live.
2 2. Ghost
Unlike Rogers, who rose up as a symbol of justice for the American people and was even made cameos on broadcasts, Barnes worked in the shadows. His training made him very calculating and taught him how the underground networks, and their business, work. He made connections with some very dangerous and resourceful individuals who helped cover his tracks and keep him off the government radar. He could even walk incognito among the public. No one expects him to drop by their front door and that gives him the element of surprise, a position of strength that could allow him to deal a deadly blow.
1 1. More Human
Haunted by the memories of the people he had slain, Barnes adopted a new approach towards compassion and this has influenced his decisions greatly. At one point, the Winter Soldier would not hesitate to put down every single man in sight to get rid of his target, but ever since rediscovering his humanity, he has taken great strides to do good. Rogers does not know what it's like to live with his failures in the same way, because he hasn't made any significant failures. Bucky's past is littered with them.