The worst-performing Marvel Cinematic Universe project may have jeopardized Yelena Belova’s development before her appearance in Thunderbolts*. The MCU timeline has spent years building up its next generation of heroes, but not every adaptation choice has been a home run. One of the MCU’s most promising newer characters – Yelena Belova, played by Florence Pugh – might never reach her full potential. And the blame might lie squarely with one of the MCU's most critically maligned shows.