The Red Guardian is the Russian counterpart of Captain America.
Alexei Shostakov was a test pilot whose death was faked by the KGB to train him as the Russian answer to Captain America, his survival being kept secret to his wife Natasha, who would become Black Widow to honor him.
The Red Guardian was under the orders of chinese ally Colonel Ling, to protect the secret weapon caled Psychotron, a machine able to create powerful illusions to trick enemies. Ling's people had captured Black Widow, so Hawkeye went to rescue her with Hercules' help, but the Red Guardian tricked Hercules into fighting a Hydra generated by the Psychotron, and defeated Hawkeye in single combat. When Red Guardian reunited the prisoner Hawkeye with Black Widow, she recognised Alexei's voice, so he revealed his identity to her.
When the rest of the Avengers went after their friends, the Red Guardian finally faced Captain America. The fight was even at first, but Cap got the upper hand due to having more experience, so Ling activated a trap to knock him out, which Red Guardian protested as he wanted his victory to be earned in a fair fight. When Black Widow sabotaged the psychotron, Ling tried to shoot her, but Alexei got in the way of the shot and was mortally wounded. Then Ling tried to shot Captain America, who was carried to safety by Hercules, but the Red Guardian jumped on Ling and made him fail the shot, which shot gas pipes whose explosion caused the eruption of a long-dormant volcano, so the molten lava buries Ling, his men and the Red Guardian.