Winter Soldier

Bucky Barnes

Played by Sebastian Stan

Bucky Barnes was Steve Rogers' closest friend and fellow World War II soldier before falling from a train and being captured by Hydra, who rebuilt him with a vibranium arm and turned him into the brainwashed assassin known as the Winter Soldier. Freed from his programming, he retains enhanced strength and reflexes from an early, unstable version of the Super Soldier Serum, and has worked to atone for decades of crimes committed under Hydra's control. Read more →

First turns up in Captain America: The Winter Soldier.