Out of the three potential Black Widow replacements that the MCU has set up so far, two of them are seemingly already going to waste. Scarlett Johansson’s Natasha Romanoff debuted in Phase 1 and was a crucial part of the original core Avengers. As Natasha’s backstory got further fleshed out, the name Black Widow started to mean more than just her hero identity. It represented the cruel Red Room, where young girls were trained to become elite spies and assassins known as Black Widows.