The "Winter Soldier" is a character from the Marvel Comics universe, primarily associated with Captain America. Originally known as Bucky Barnes, he was thought to be dead but was later revealed to have been captured and brainwashed by the Soviet Union. As the Winter Soldier, he becomes a skilled assassin, using advanced technology and combat skills to carry out missions. In the Marvel Cinematic Universe, the Winter Soldier is portrayed by Sebastian Stan. His story explores themes of identity, redemption, and the impact of war. Eventually, he seeks to break free from his past and reconnect with his friend, Steve Rogers, also known as Captain America.