This is the most current version of Scarlet Witch, as she was last seen in Captain America: Civil War.
Wanda Maximoff aka Scarlet-Witch had seemed to form a bond with Steve Rogers, and worked closely with him in the beginning of Captain America: Civil War. As the events unfold, there is no love lost for Tony Stark, but her relationship with Vision is what really takes the hit. All of this proving to be great development for her character, and making her much more interesting and sympathetic in my opinion.
Scarlet Witch “Age of Ultron”
Wanda Maximoff, also known as Scarlet Witch made her MCU debut in Avengers: Age of Ultron. Starting out villainous, her and her brother Quicksilver form an alliance with the titular automaton.
In the Marvel Comic Books, Wanda Maximoff aka Scarlet Witch was a Mutant. Later it was revealed she was Magneto’s daughter. Later still, it was revealed that wasn’t true after all, and her and her brother Quicksilver had been genetic experiments. The MCU kind of took this approach, since they are unable to reference “Mutants” due to licensing issues. In the post credits scene from Captain America: The Winter Soldier, they are shown being held captive by Hydra and it is implied that Loki’s staff was the source of their powers.
Scarlet Witch Age of Ultron ending “New Avengers”
In Age of Ultron, when Scarlet Witch finally discovers Ultron‘s true motivations, she has a change of heart. Scarlet Witch and her brother Quicksilver form an alliance with The Avengers in order to stop Ultron. Hawkeye motivates her in a moment of doubt, then she comes out swinging, ready to take on as many Ultron drones as possible.
After dealing the final death blow to Ultron by literally crushing his “Heart” Scarlet Witch is taken in as an Avenger. Scarlet Witch New Avengers Version is seen in new attire when Captain America and Black Widow assemble a New Avengers team in the Avengers facility.
Actress Elizabeth Olsen has portrayed Scarlet Witch in two MCU films so far, and has been seemingly confirmed to appear in the upcoming Avengers: Infinity War!