Winter Soldier

The Winter Soldier is a Marvel Supervillain that fight the superhero Captain America. He was originally both Captain America's friend and sidekick during World War 2.

As Bucky
As James Barnes, AKA Bucky he lost his father, during WWII, and was adopted by Camp Lehigh. It was here that he learned the identity of Captain America. He was trained by Caprain America and was assigned to be Cap's sidekick. There he accompanyed him on many adventures, and the duo usually worked with the original Invaders. However, on thier final mission together against Baron Zemo, Bucky and Cap hopped on an experimental drone plane in an attempt to disarm a bomb. When bomb detonated, dropping Cap in the North Atlantic, where he would later be found frozen in time and thawed out by the Avengers. The American forces never found Bucky's body, and he was presumed dead. Not knowing that Bucky was both found and revived by Russian General; Vasily Karpov.

As Winter Soldier
When Bucky awoke, he had no memory of his real identity, which gave Karpov an opportunity to reprogram Bucky as a Soviet assassin called the Winter Soldier. He was sent all across the globe, committing political assassinations with huge effects on the Cold War. However, his memory implantation caused mental instability, and he was kept in stasis between missions to prevent rebellion.