Scarlett Johansson's Black Widow and Elizabeth Olsen's Scarlet Witch appeared in a lot of MCU movies together, and here's how their outings rank. Johansson joined the MCU as Natasha Romanoff starting with 2010's Iron Man 2, and the character evolved from "hyper-sexualized" - as the actress herself would later state - eye candy to a fully fleshed-out superhero. Johansson got to explore the full emotional range of Natasha and said goodbye to the role following 2021's Black Widow. Sadly, the release of her final outing would later be overshadowed by the resulting controversy over her lawsuit against Disney, and their response to it.
Elizabeth Olsen had a somewhat similiar journey with her MCU outings. The character was somewhat sidelined during earlier appearances, but in recent years - and especially following her Disney+ series WandaVision - Wanda Maximoff / Scarlet Witch has gradually risen to become one of the franchise's most unique and layered heroes.
Sadly, Johansson and Olsen didn't share much screentime across their MCU movies, though they both appeared in quite a few of the same entries.
Avengers: Age Of Ultron (2015)
Joss Whedon's Avengers: Age Of Ultron properly introduced Wanda and her ill-fated brother Pietro, in addition to new villain Ultron, Paul Bettany's Vision, the seeds of an idealogical clash between Tony Stark and Steve Rogers and much more. For that reason, Age Of Ultron feels overstuffed and often buckles under the weight of so many stories. It served as a good introduction to Wanda, though it was criticized for Natasha's sudden love story with Bruce Banner and especially her "monster" line.
Avengers: Infinity War (2018)
Avengers: Infinity War had even more elements to juggle than Age Of Ultron, including making Thanos the main threat - and technically, protagonist - while nearly every major MCU superhero played a role. The love story between Scarlet Witch and Vision was the beating heart of it - with Olsen often stealing the show - and it features some of the most iconic moments of the MCU thus far.
Captain America: Civil War (2016)
The Russos' second MCU outing felt like Avengers 2.5 in many ways, though like the Wanda/Vision story anchored Infinity War, the friendship between Cap and Bucky held all the other stories together. Both Olsen and Johansson aren't left with much to do in this entry, but even then, they make an impression.
Avengers: Endgame (2019)
Endgame was the cumulation of a decade of the MCU, and in addition to being loaded with easter eggs and callbacks, it manages to wrap up many of the major storylines of the franchise up to that point. It's an impressive narrative balancing act and one that results in lots of great setpieces, character beats and shock deaths. Olsen's Scarlet Witch only really cameos in this outing, though Natasha plays a major role in the story and its outcome.
Captain America: The Winter Soldier (2014)
Captain America: The Winter Soldier is arguably the best movie of the MCU full stop, being a character-focused blockbuster that blended action with an exciting conspiracy plotline. The events of the sequel had some major ramifications in the series, including SHIELD being dismantled and Bucky's introduction as the titular assassin, while the film is one of the MCU's more standalone entries. It's also the outing that really bonded Scarlett Johansson's Black Widow to Steve, though Elizabeth Olsen's Scarlet Witch only makes a tiny cameo during the credits.