Who he is: The Winter Soldier, a.k.a. Bucky Barnes
His power: The Winter Soldier has enhanced speed, strength, stamina, and durability, though the extent of his chemically enhanced powers isn’t clear. His greatest asset is a robotic arm possessing force far greater than most any strength, even challenging Captain America’s.
His story: As seen in Captain America: The First Avenger, Bucky Barnes was Steve Rogers’ best friend, growing up with him in Brooklyn before going off to serve. Bucky got kidnapped by Hydra during World War II, prompting Rogers to grab his shield and stage a one-man rescue mission. Rogers saved Bucky and a bunch of other soldiers, including future Howling Commandos member Dum Dum Dugan. Unfortunately, during one of the Howling Commandos’ missions, Bucky fell from a moving Hydra chain and was presumed dead.
He survived, though, and while the next few decades are a blur to both the audience and Bucky, we know from The Winter Soldier that he was saved by the Soviets and/or Hydra. Having lost an arm, he was given a high-tech prosthetic by the Soviets/Hydra and then brainwashed into becoming an emotionless assassin who was kept cryogenically frozen when not in use. Under Hydra’s control, Bucky—now The Winter Soldier—killed a bunch of people, including Howard and Maria Stark. When Hydra made its big play and revealed that it had taken over S.H.I.E.L.D., Captain America realized his old friend was still alive and tried to force him to regain his memories.
In Civil War, Bucky is blamed for a bombing that killed T’Chaka, the king of Wakanda and father of T’Challa, the Black Panther. The bombing was actually committed by Helmut Zemo, who discovered the mind-control code words that Hydra had used on Bucky and forced him to reveal the location of other Winter Soldiers trained by Hydra. Bucky eventually breaks free from the mind control, and he goes to Siberia with Captain America to stop Zemo. Iron Man follows and discovers that Bucky killed his parents, prompting a superhero fight, but both Cap and Bucky manage to get away.
Cleared of the bombing, Bucky is granted asylum in Wakanda and willingly re-frozen, hoping that Wakanda’s scientists can someday cure his brainwashing.
Played by: Sebastian Stan
Currently, The Winter Soldier is: Chilling out in Wakanda.
Where will we see him next? Unknown, but he’ll probably pop up in Avengers: Infinity War.w