For years, Captain America believed his partner dead, but the Russians came upon Barnes' body in the ocean and turned the amnesiac into the perfect killing machine. Upon proving difficult to control, the Russians decided to put him in cryo-freeze between missions, giving birth to the legendary Winter Soldier.
Bucky's strength was greatly boosted by a serum given to him by HYDRA scientists. The Winter Soldier's physical strength is enhanced to superhuman levels.
James Buchanan “Bucky” Barnes enlists to fight in World War II, but eventually literally falls in battle. Unfortunately, the evil Arnim Zola recovers him and erases his memory, turning him into a highly-trained assassin called the Winter Soldier.
Aside from the bullies picking on his pal Rogers, Barnes' first real enemies were the Nazis and the Nazi science division known as HYDRA. In particular, the HYDRA scientist Arnim Zola who turned Barnes into the Winter Soldier earns his enmity.
Unbeknownst to his team, Barnes' enhanced abilities allowed him to survive the fall, albeit with the loss of his left arm. Once he was found by the Soviet Armed Forces and HYDRA, Barnes was brainwashed and armed with a new cybernetic arm in order to become their operative, known as the Winter Soldier.
Why did Captain America choose Falcon and not Bucky?
The Steve of the MCU would never choose Bucky to replace him as Captain America. This is not because of Bucky's past nor because Steve doesn't think he could do well. Rather, as his best friend, Steve knows that the last thing Bucky needs is another mission and codename to live up to.
Bucky Barnes, like Steve Rogers, has lived for several decades due to cryogenic freezing and the super-soldier serum. Bucky's life expectancy could potentially surpass Steve's 116 years, depending on circumstances. Despite outwardly aging at the same rate as Steve, Bucky can still live for at least another 80 years.
"Seventeen" could hold any number of connotations, like maybe Bucky was the 17th test subject on which this brainwashing was tested. "Benign" could reference his state of inactivity between missions, whilst "Nine" can refer to the Greek myth of the Hydra, which has nine heads.
Bucky was captured by Hydra in 1945, received experimentation with a variant of the Super-Soldier Serum, was brainwashed, and was implanted with a metal arm made of titanium to replace the left arm that was amputated when he fell from a train and plummeted nearly to his death.
The fact that Bucky did wear the arm is why it disappeared according to the Russo brothers (via Comicbook), as they stated anything that was part of someone's identity would disappear when snapped.
It turns out that Bucky survived his fall, but was found by HYDRA and brainwashed into an assassin operative of HYDRA as The Winter Soldier. He is first seen when Nick Fury was being chased by rogue policemen sent by Pierce to kill him. He shoots a grenade at Fury's car and made it fly into the air.
While at the HYDRA Siberian Facility, Barnes' prosthetic arm was destroyed by Tony Stark's unibeam, after Stark was manipulated by Helmut Zemo and attacked Barnes and Steve Rogers.
Of course, he's one of the exceptions as he turned evil even before becoming the Avenger. Bucky was a hero who fought alongside Steve Rogers in World War Two. But when he was captured and brainwashed, he became an assassin known as the Winter Soldier.
As a villain, it made sense to present the Winter Soldier as unstoppable, to make him a better foil for the heroes he fought. With his reformation comes an increased vulnerability; physically weakening him helps the audience better identify with him and ensures he can't simply knock out opponents with one punch.
Bucky owes his youthful appearance to repeated cryo-freezes orchestrated by the Russians. He possesses no super powers and never received a form of the Super Soldier Serum as many assume, but continues to operate at peak human ability.
Usually, Captain America is considered the best fighter in the Marvel Universe, but on this occasion Bucky beat him fair and square, even using Steve's own shield to deliver the final blow. The power levels of Marvel characters vary greatly according to writers' preferences and story needs.
His family is long dead, he has to wear gloves to cover his vibranium murder arm, and even his friendships are rooted in a desire to atone for past sins. Obviously I have never experienced what the Winter Soldier has, but I do find my own trauma is often exposed on first dates.
The Hydra experimentation on Barnes causes him to survive his fall, and he is recaptured by the Hydra wing of the Soviet Union, where he is tortured and brainwashed by Arnim Zola and turned into the Winter Soldier, a mind-controlled super soldier with a metal prosthetic arm.
The fact of the matter is, the arm still functions as a part of his body. The superpowered enhancements do not change the fact that he will still naturally experience pain when his body is put under such stress, especially when the arm is attached to so many nerves that could've been damaged from losing his actual arm.
In the MCU, White Wolf is the name some local Wakandan kids started calling Bucky as seen in the post-credit scene from Black Panther. In Infinity War, T'Challa confirms White Wolf is how Bucky is known now by the Wakandans.
This “little calm” is actually something we've seen before in the post-credits scene of Black Panther, where Bucky is showing sans metal arm in a hut, where Wakandan children call him “White Wolf.” It's not just another alias to add to Bucky's rolodex — it's potentially a huge sign of things to come for the Winter ...
Because Steve said those magic words: “Don't do anything stupid until I get back.” Those were Bucky's last words to Steve before he left to fight in WW2.
We see that he's deprogrammed 6 months before the snap in FATWS. He's then snapped away and comes back 5 years later. FATWS takes place 6 months after he comes back. So Bucky is likely 33 physically while chronologically being 107 (FATWS takes place in April 2024, so Bucky's wrong about being 106).
Even Bucky's variant serum should allow him to age normally (unless he gets frozen again). A side effect of the Super-Soldier Serum that the Winter Soldier shares with Captain America is that neither can get drunk.
Before Bucky Barnes and Natasha Romanoff face off in 'Captain America: Cold War,' rediscover their history together, from the Red Room to the Avengers and beyond.
