Captain America and Black Widow are very good friends in the Marvel Universe. But after the Kree-Shi’ar War, Cap leaves and Black Widow takes his place as the team leader. They care deeply for each other and for their friends. But the war was not without its tragedy. She was grieved by the deaths of Iron Man, Captain America, and Nick Fury. She also blames herself for the events of the Onslaught.
As a super soldier, she’s able to defeat super villains. In her past life, she had worked for the S.H.I.E.L.D. team and aided the Avengers in missions. But she was also a spy herself and was captured by General Yuri Brushov. She was then taken away from the team, but not before discovering her husband was alive. She went to Russia to kill him and became the “Red Guardian.” While she was working for the Avengers, she was also atoning for her past crimes. She worked for paid jobs outside of Avengers missions and put money into trusts for her family and friends.
Natasha Romanoff, the Russian spy, is a highly skilled assassin who often works for S.H.I.E.L.D. She’s a trained spy, as well as a trained martial artist. Her skill and precision allow her to strike fear into her enemies. She used to be a spy on the side of evil, but she’s now a member of the Avengers team.