Antonia Dreykov

Set immediately after Civil War, while Natasha is a fugitive. She reunites with her fake Soviet sleeper-cell family from childhood: sister Yelena Belova, "father" Alexei Shostakov / Red Guardian, and "mother" Melina Vostokoff. They destroy the Red Room, the programme that trained and chemically conditioned Black Widows, killing its director Dreykov. His daughter Antonia, whom Natasha believed she had killed and who was in fact turned into the mind-controlled Taskmaster, is freed.

Taskmaster is Antonia Dreykov, the director's daughter. Natasha blew up a building to kill Dreykov and believed she'd killed Antonia too. Antonia survived, disfigured, and her father installed technology letting her instantly copy any fighting style she observes. She's freed at the end.

This is the origin point for four current Doomsday roster members. Yelena, Alexei, Ghost (from elsewhere), and Taskmaster all route through the Thunderbolts, and Yelena in particular becomes one of the most important characters in the current phase.

Valentina Allegra de Fontaine, CIA director facing impeachment, sends four of her expendable operatives — Yelena Belova, John Walker, Ghost (Ava Starr), and Taskmaster — to a facility to unknowingly kill each other and erase evidence of Project Sentry.